Re: exec and traceback
ken...@gameofy.com writes: > I'm using exec() to run a (multi-line) string of python code. If an > exception occurs, I get a traceback containing a stack frame for the > string. I've labeled the code object with a "file name" so I can > identify it easily, and when I debug, I find that I can interact with > the context of that stack frame, which is pretty handy. > > What I would like to also be able to do is make the code string > visible to the debugger so I can look at and step through the code in > the string as if it were from a python file. The debugger may not be prepared for this kind of source; thus, you might need a much more intelligent debugger. The "exec" itself works with arbitary strings, not only with string constants coming from a source file. It has no way to reliably associate a filename and a line number in the respective file with the code lines. The debugger (at least currently) expects to locate the source code in a file (maybe an archive) given a line number in that file. Based on this, I expect that your wish will be difficult to fulfill. -- https://mail.python.org/mailman/listinfo/python-list
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Re: python to C code generator
On Wednesday, January 17, 2018 at 4:34:23 PM UTC+5:30, kushal bhattacharya wrote: > Hi, > Is there any python framework or any tool as which can generate C code from > python code as it is . > > Thanks, > Kushal hi, I have found nuitka as asuitable candidate but it seems that nuitka doesnt generate a simple C code which could be included as a C file in another program.Is there any alternative easier way regarding this? Thanks -- https://mail.python.org/mailman/listinfo/python-list
Re: python to C code generator
What about Cython? On 01/23/2018 01:25 PM, kushal bhattacharya wrote: On Wednesday, January 17, 2018 at 4:34:23 PM UTC+5:30, kushal bhattacharya wrote: Hi, Is there any python framework or any tool as which can generate C code from python code as it is . Thanks, Kushal hi, I have found nuitka as asuitable candidate but it seems that nuitka doesnt generate a simple C code which could be included as a C file in another program.Is there any alternative easier way regarding this? Thanks -- https://mail.python.org/mailman/listinfo/python-list
Re: python to C code generator
On Wednesday, January 17, 2018 at 4:34:23 PM UTC+5:30, kushal bhattacharya wrote: > Hi, > Is there any python framework or any tool as which can generate C code from > python code as it is . > > Thanks, > Kushal yes i have but it generates a complex C code with python dependencies.I want to call the generated function from another C code but i Cant figure out how to do that -- https://mail.python.org/mailman/listinfo/python-list
Re: python to C code generator
On 23/01/2018 13:23, kushal bhattacharya wrote: On Wednesday, January 17, 2018 at 4:34:23 PM UTC+5:30, kushal bhattacharya wrote: Hi, Is there any python framework or any tool as which can generate C code from python code as it is . Thanks, Kushal yes i have but it generates a complex C code with python dependencies.I want to call the generated function from another C code but i Cant figure out how to do that Because the translation isn't simply defined. I've just tried nuitka on the Python code 'a=b+c', and it generates 2400 lines of C. The main purpose seems to be to generate a self-contained executable corresponding to the Python, but generating first a C equivalent then using a C compiler and linker. This equivalent code may just contain all the bits in CPython needed to do the job, but bypassing all the stuff to do with executing actual byte-code. But it also seems to do some optimisations (in the generated C before it uses C compiler optimisations), so that if static types can be inferred it might make use of that info. Perhaps you simply want to use Python syntax to write C code? That would be a different kind of translator. And a simpler one, as 'a=b+c' translates to 'a+b+c;' in C. -- bartc -- https://mail.python.org/mailman/listinfo/python-list
Re: python to C code generator
On Tuesday, January 23, 2018 at 7:05:02 PM UTC+5:30, bartc wrote: > On 23/01/2018 13:23, kushal bhattacharya wrote: > > On Wednesday, January 17, 2018 at 4:34:23 PM UTC+5:30, kushal bhattacharya > > wrote: > >> Hi, > >> Is there any python framework or any tool as which can generate C code > >> from python code as it is . > >> > >> Thanks, > >> Kushal > > > > yes i have but it generates a complex C code with python dependencies.I > > want to call the generated function from another C code but i Cant figure > > out how to do that > > Because the translation isn't simply defined. > > I've just tried nuitka on the Python code 'a=b+c', and it generates 2400 > lines of C. The main purpose seems to be to generate a self-contained > executable corresponding to the Python, but generating first a C > equivalent then using a C compiler and linker. > > This equivalent code may just contain all the bits in CPython needed to > do the job, but bypassing all the stuff to do with executing actual > byte-code. But it also seems to do some optimisations (in the generated > C before it uses C compiler optimisations), so that if static types can > be inferred it might make use of that info. > > Perhaps you simply want to use Python syntax to write C code? That would > be a different kind of translator. And a simpler one, as 'a=b+c' > translates to 'a+b+c;' in C. > > -- > bartc This is exactly what i meant to say.My goal is to translate the python code into its C equivalent with function name as it is. -- https://mail.python.org/mailman/listinfo/python-list
Re: python to C code generator
On 1/23/18 8:48 AM, kushal bhattacharya wrote: On Tuesday, January 23, 2018 at 7:05:02 PM UTC+5:30, bartc wrote: On 23/01/2018 13:23, kushal bhattacharya wrote: On Wednesday, January 17, 2018 at 4:34:23 PM UTC+5:30, kushal bhattacharya wrote: Hi, Is there any python framework or any tool as which can generate C code from python code as it is . Thanks, Kushal yes i have but it generates a complex C code with python dependencies.I want to call the generated function from another C code but i Cant figure out how to do that Because the translation isn't simply defined. I've just tried nuitka on the Python code 'a=b+c', and it generates 2400 lines of C. The main purpose seems to be to generate a self-contained executable corresponding to the Python, but generating first a C equivalent then using a C compiler and linker. This equivalent code may just contain all the bits in CPython needed to do the job, but bypassing all the stuff to do with executing actual byte-code. But it also seems to do some optimisations (in the generated C before it uses C compiler optimisations), so that if static types can be inferred it might make use of that info. Perhaps you simply want to use Python syntax to write C code? That would be a different kind of translator. And a simpler one, as 'a=b+c' translates to 'a+b+c;' in C. -- bartc This is exactly what i meant to say.My goal is to translate the python code into its C equivalent with function name as it is. The best way to do that is to read the Python code, understand what it does, and re-write it in C. You won't find an automatic tool that can do the job you want. The semantics of Python and C are too different. --Ned. -- https://mail.python.org/mailman/listinfo/python-list
Re: python to C code generator
You can look at SymPy code generator http://docs.sympy.org/latest/modules/utilities/codegen.html Perhaps this is exactly what you need. With kind regards, -gdg 2018-01-23 17:00 GMT+03:00 Ned Batchelder : > On 1/23/18 8:48 AM, kushal bhattacharya wrote: > >> On Tuesday, January 23, 2018 at 7:05:02 PM UTC+5:30, bartc wrote: >> >>> On 23/01/2018 13:23, kushal bhattacharya wrote: >>> On Wednesday, January 17, 2018 at 4:34:23 PM UTC+5:30, kushal bhattacharya wrote: > Hi, > Is there any python framework or any tool as which can generate C > code from python code as it is . > > Thanks, > Kushal > yes i have but it generates a complex C code with python dependencies.I want to call the generated function from another C code but i Cant figure out how to do that >>> Because the translation isn't simply defined. >>> >>> I've just tried nuitka on the Python code 'a=b+c', and it generates 2400 >>> lines of C. The main purpose seems to be to generate a self-contained >>> executable corresponding to the Python, but generating first a C >>> equivalent then using a C compiler and linker. >>> >>> This equivalent code may just contain all the bits in CPython needed to >>> do the job, but bypassing all the stuff to do with executing actual >>> byte-code. But it also seems to do some optimisations (in the generated >>> C before it uses C compiler optimisations), so that if static types can >>> be inferred it might make use of that info. >>> >>> Perhaps you simply want to use Python syntax to write C code? That would >>> be a different kind of translator. And a simpler one, as 'a=b+c' >>> translates to 'a+b+c;' in C. >>> >>> -- >>> bartc >>> >> >> This is exactly what i meant to say.My goal is to translate the python >> code into its C equivalent with function name as it is. >> > > The best way to do that is to read the Python code, understand what it > does, and re-write it in C. You won't find an automatic tool that can do > the job you want. The semantics of Python and C are too different. > > --Ned. > -- > https://mail.python.org/mailman/listinfo/python-list > -- https://mail.python.org/mailman/listinfo/python-list
Re: python to C code generator
Id go this way too. Basic C is straightforward. I usually consider learning a new "thing " if the time to support potwntially combersome solution using existing methods justifies the effort. On Jan 23, 2018 09:01, "Ned Batchelder" wrote: > On 1/23/18 8:48 AM, kushal bhattacharya wrote: > >> On Tuesday, January 23, 2018 at 7:05:02 PM UTC+5:30, bartc wrote: >> >>> On 23/01/2018 13:23, kushal bhattacharya wrote: >>> On Wednesday, January 17, 2018 at 4:34:23 PM UTC+5:30, kushal bhattacharya wrote: > Hi, > Is there any python framework or any tool as which can generate C > code from python code as it is . > > Thanks, > Kushal > yes i have but it generates a complex C code with python dependencies.I want to call the generated function from another C code but i Cant figure out how to do that >>> Because the translation isn't simply defined. >>> >>> I've just tried nuitka on the Python code 'a=b+c', and it generates 2400 >>> lines of C. The main purpose seems to be to generate a self-contained >>> executable corresponding to the Python, but generating first a C >>> equivalent then using a C compiler and linker. >>> >>> This equivalent code may just contain all the bits in CPython needed to >>> do the job, but bypassing all the stuff to do with executing actual >>> byte-code. But it also seems to do some optimisations (in the generated >>> C before it uses C compiler optimisations), so that if static types can >>> be inferred it might make use of that info. >>> >>> Perhaps you simply want to use Python syntax to write C code? That would >>> be a different kind of translator. And a simpler one, as 'a=b+c' >>> translates to 'a+b+c;' in C. >>> >>> -- >>> bartc >>> >> >> This is exactly what i meant to say.My goal is to translate the python >> code into its C equivalent with function name as it is. >> > > The best way to do that is to read the Python code, understand what it > does, and re-write it in C. You won't find an automatic tool that can do > the job you want. The semantics of Python and C are too different. > > --Ned. > -- > https://mail.python.org/mailman/listinfo/python-list > -- https://mail.python.org/mailman/listinfo/python-list
Re: python to C code generator
On Wednesday, January 17, 2018 at 4:34:23 PM UTC+5:30, kushal bhattacharya wrote: > Hi, > Is there any python framework or any tool as which can generate C code from > python code as it is . > > Thanks, > Kushal ok so which python tool would be the best one which can be included and parameters can be passed to from another C code file -- https://mail.python.org/mailman/listinfo/python-list
[RELEASED] Python 3.4.8rc1 and Python 3.5.5rc1 are now available
On behalf of the Python development community, I'm pleased to announce the availability of Python 3.4.8rc1 and Python 3.5.5rc1. Both Python 3.4 and 3.5 are in "security fixes only" mode. Both versions only accept security fixes, not conventional bug fixes, and both releases are source-only. You can find Python 3.4.8rc1 here: https://www.python.org/downloads/release/python-348rc1/ And you can find Python 3.5.5rc1 here: https://www.python.org/downloads/release/python-355rc1/ Happy Pythoning, //arry/ -- https://mail.python.org/mailman/listinfo/python-list
Re: Why is there no functional xml?
Rustom Mody wrote:
> Its obviously easier in python to put optional/vararg parameters on the
> right side rather than on the left of a parameter list.
> But its not impossible to get it in the desired order — one just has to
> 'hand-parse' the parameter list received as a *param
> Thusly:
> appointments = E.appointments(
>{"reminder":"15"},
>E.appointment(
> E.begin(1181251680),
> E.uid("04008200E000"),
> E.alarmTime(1181572063),
> E.state(),
> E.location(),
> E.duration(1800),
> E.subject("Bring pizza home")
> )
> )
Let's not waste too much effort on minor aesthic improvements ;)
>> Personally I'd probably avoid the extra layer and write a function that
>> directly maps dataclasses or database records to xml using the
>> conventional elementtree API.
>
> I dont understand…
> [I find the OO/imperative style of making a half-done node and then
> [throwing
> piece-by-piece of contents in/at it highly aggravating]
What I meant is that once you throw a bit of introspection at it much of the
tedium vanishes. Here's what might become of the DOM-creation as part of an
actual script:
import xml.etree.ElementTree as xml
from collections import namedtuple
Appointment = namedtuple(
"Appointment",
"begin uid alarmTime state location duration subject"
)
appointments = [
Appointment(
begin=1181251680,
uid="04008200E000",
alarmTime=1181572063,
state=None,
location=None,
duration=1800,
subject="Bring pizza home"
)
]
def create_dom(appointments, reminder):
node = xml.Element("zAppointments", reminder=str(reminder))
for appointment in appointments:
for name, value in zip(appointment._fields, appointment):
child = xml.SubElement(node, name)
if value is not None:
child.text = str(value)
return node
with open("appt.xml", "wb") as outstream:
root = create_dom(appointments, 15)
xml.ElementTree(root).write(outstream)
To generalize that to handle arbitrarily nested lists and namedtuples a bit
more effort is needed, but I can't see where lxml.objectify could make that
much easier.
--
https://mail.python.org/mailman/listinfo/python-list
Re: Why is there no functional xml?
Rustom Mody wrote: > On Sunday, January 21, 2018 at 4:51:34 PM UTC+5:30, Peter Otten wrote: >> Personally I'd probably avoid the extra layer and write a function that >> directly maps dataclasses or database records to xml using the >> conventional elementtree API. > > Would appreciate your thoughts/comments Peter! > > I find that you can get 'E' from lxml.objectify as well as lxml.builder > builder seems better in that its at least sparsely documented > objectify seems to have almost nothing beyond the original David Mertz' > docs > > builder.E seems to do what objectify.E does modulo namespaces > > builder.E and objectify.E produce types that are different and look > backwards (at least to me — Elementbase is less base than _Element) > > You seem to have some reservation against objectify, preferring the > default Element — I'd like to know what While I don't have any actual experience with it, my gut feeling is that it simplifies something that is superfluous to begin with. > Insofar as builder seems to produce the same type as Element unlike > objectify which seems to be producing a grandchild type, do you have the > same reservations against builder.E? If I understand you correctly you are talking about implementation details. Unfortunately I cannot comment on these -- I really just remembered objectify because of the catchy name... -- https://mail.python.org/mailman/listinfo/python-list
Re: python to C code generator
Hey Ally, Cython adds a big chunk of complexity to simple things. That's the problem. Greetings. On 01/23/2018 01:54 PM, ally.m...@bankmail.host wrote: Have you tried cython ? On 01/23/2018 01:25 PM, kushal bhattacharya wrote: On Wednesday, January 17, 2018 at 4:34:23 PM UTC+5:30, kushal bhattacharya wrote: Hi, Is there any python framework or any tool as which can generate C code from python code as it is . Thanks, Kushal hi, I have found nuitka as asuitable candidate but it seems that nuitka doesnt generate a simple C code which could be included as a C file in another program.Is there any alternative easier way regarding this? Thanks -- https://mail.python.org/mailman/listinfo/python-list
Re: python to C code generator
On Wed, Jan 24, 2018 at 1:45 AM, wrote: > Hey Ally, > > Cython adds a big chunk of complexity to simple things. That's the problem. That's like saying "Unicode adds a big chunk of complexity to the simple task of translating a word from Japanese into Russian". No, it doesn't; the complexity is inherent in the problem. You cannot translate Python code into C code without either (a) reimplementing all of Python's semantics, as Cython does; or (b) drastically changing the semantics, such that even the very simplest of code might behave quite differently; or (c) manually reading through the code and writing equivalent C, which is what you might call "porting" or "rewriting". (Or possibly "prototyping", if the intention was always to transform it into C.) There is fundamentally NO easy way to translate code from one language into another and get readable, idiomatic code at the other end. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: python to C code generator
On 23/01/2018 13:34, bartc wrote: Perhaps you simply want to use Python syntax to write C code? That would > be a different kind of translator. And a simpler one, as 'a=b+c' > translates to 'a+b+c;' in C. Or rather, 'a=b+c;' (I've written source to source translators, some of which could target C, but not Python to C. It would be feasible to write C code in a syntax that looks rather like Python, but it won't be real Python, and you can't run it as Python. It wouldn't be a satisfactory way of writing C programs. So, although I'm not that big a fan of C syntax, it might be better to write C as C, and Python as Python, to avoid confusion.) -- bartc -- https://mail.python.org/mailman/listinfo/python-list
Processing a key pressed in Python 3.6
I would appreciate help on finding a solution to following problem. This
is the general structure of the "problem" code:
while True
# Get some data from the web and process it
...
...
# Write these data to a file
...
...
# Check if a_key has been pressed in the command window
...
...
if a_key_pressed:
# Perform some pre-termination tasks
...
...
# Close the output data file
...
...
raise SystemExit('Exit')
I am running the code with Python 3.6 on a windows 10 platform. I have
tried many approaches (mainly those posted on stackoverflow) but I have
yet to find an approach that works for this structure.
Note:
1) The code is executed in the windows 10 command window
2) I am not using wxPython, IDLE, or pyGame in this application.
3) The time to get the data, process it and write it to a file can
take from 0.5 sec to 1.5 sec
4) The key hit need not be echoed to the command window
--
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Re: Processing a key pressed in Python 3.6
On Wed, Jan 24, 2018 at 5:50 AM, Virgil Stokes wrote:
> I would appreciate help on finding a solution to following problem. This is
> the general structure of the "problem" code:
>
>> while True
>> # Get some data from the web and process it
>> ...
>> ...
>> # Write these data to a file
>> ...
>> ...
>> # Check if a_key has been pressed in the command window
>> ...
>> ...
>> if a_key_pressed:
>> # Perform some pre-termination tasks
>> ...
>> ...
>> # Close the output data file
>> ...
>> ...
>> raise SystemExit('Exit')
>
>
> I am running the code with Python 3.6 on a windows 10 platform. I have tried
> many approaches (mainly those posted on stackoverflow) but I have yet to
> find an approach that works for this structure.
>
> Note:
> 1) The code is executed in the windows 10 command window
> 2) I am not using wxPython, IDLE, or pyGame in this application.
> 3) The time to get the data, process it and write it to a file can
> take from 0.5 sec to 1.5 sec
> 4) The key hit need not be echoed to the command window
>
Are you okay with demanding a specific key, rather than simply "press
any key"? Even better, key combination? Handle Ctrl-C by catching
KeyboardInterrupt and you can take advantage of Python's existing
cross-platform handling of the standard interrupt signal.
If Ctrl-C won't work for you, how about stipulating that it be Enter?
"Press Enter to quit" isn't too much worse than "Press any key to
quit" (plus you have less chance of accidentally terminating the
program when you don't want to). Spin off a thread to wait for enter.
I've tested this only on Linux, but it ought to work:
import threading
import time
shutdown = False
def wait_for_enter():
print("Hit Enter to quit.")
input()
global shutdown; shutdown = True
threading.Thread(target=wait_for_enter).start()
while "more work to do":
print("Getting data...")
time.sleep(1)
print("Saving data to file...")
time.sleep(1)
if shutdown:
print("Pre-termination...")
time.sleep(1)
raise SystemExit("exit")
If it doesn't, try switching around which is the secondary thread and
which is the primary - spin off a thread to do the work, then call
input() in the main thread.
ChrisA
--
https://mail.python.org/mailman/listinfo/python-list
Re: Processing a key pressed in Python 3.6 🦉
Thanks very much Chris,
This code worked perfectly for "Enter". Your knowledge of Python and
more specifically this elegant solution are greatly appreciated. I now
know that I need to learn more about threads. :-)
On 2018-01-23 20:15, Chris Angelico wrote:
On Wed, Jan 24, 2018 at 5:50 AM, Virgil Stokes wrote:
I would appreciate help on finding a solution to following problem. This is
the general structure of the "problem" code:
while True
# Get some data from the web and process it
...
...
# Write these data to a file
...
...
# Check if a_key has been pressed in the command window
...
...
if a_key_pressed:
# Perform some pre-termination tasks
...
...
# Close the output data file
...
...
raise SystemExit('Exit')
I am running the code with Python 3.6 on a windows 10 platform. I have tried
many approaches (mainly those posted on stackoverflow) but I have yet to
find an approach that works for this structure.
Note:
1) The code is executed in the windows 10 command window
2) I am not using wxPython, IDLE, or pyGame in this application.
3) The time to get the data, process it and write it to a file can
take from 0.5 sec to 1.5 sec
4) The key hit need not be echoed to the command window
Are you okay with demanding a specific key, rather than simply "press
any key"? Even better, key combination? Handle Ctrl-C by catching
KeyboardInterrupt and you can take advantage of Python's existing
cross-platform handling of the standard interrupt signal.
If Ctrl-C won't work for you, how about stipulating that it be Enter?
"Press Enter to quit" isn't too much worse than "Press any key to
quit" (plus you have less chance of accidentally terminating the
program when you don't want to). Spin off a thread to wait for enter.
I've tested this only on Linux, but it ought to work:
import threading
import time
shutdown = False
def wait_for_enter():
print("Hit Enter to quit.")
input()
global shutdown; shutdown = True
threading.Thread(target=wait_for_enter).start()
while "more work to do":
print("Getting data...")
time.sleep(1)
print("Saving data to file...")
time.sleep(1)
if shutdown:
print("Pre-termination...")
time.sleep(1)
raise SystemExit("exit")
If it doesn't, try switching around which is the secondary thread and
which is the primary - spin off a thread to do the work, then call
input() in the main thread.
ChrisA
--
https://mail.python.org/mailman/listinfo/python-list
plot / graph connecting re ordered lists
Looking for suggestions. I have an ordered list of names these names will be reordered. I am looking to make a plot, graph, with the two origins of the names in separate columns and a line connecting them to visually represent how much they have moved in the reordering. Surely there is some great example code for this on the net an am not finding a clean example. Thanks Vincent Davis -- https://mail.python.org/mailman/listinfo/python-list
Re: Processing a key pressed in Python 3.6
Another follow-up question:
How would this code be modified to handle using the "Esc" key instead of
the "Enter" key?
On 2018-01-23 20:15, Chris Angelico wrote:
On Wed, Jan 24, 2018 at 5:50 AM, Virgil Stokes wrote:
I would appreciate help on finding a solution to following problem. This is
the general structure of the "problem" code:
while True
# Get some data from the web and process it
...
...
# Write these data to a file
...
...
# Check if a_key has been pressed in the command window
...
...
if a_key_pressed:
# Perform some pre-termination tasks
...
...
# Close the output data file
...
...
raise SystemExit('Exit')
I am running the code with Python 3.6 on a windows 10 platform. I have tried
many approaches (mainly those posted on stackoverflow) but I have yet to
find an approach that works for this structure.
Note:
1) The code is executed in the windows 10 command window
2) I am not using wxPython, IDLE, or pyGame in this application.
3) The time to get the data, process it and write it to a file can
take from 0.5 sec to 1.5 sec
4) The key hit need not be echoed to the command window
Are you okay with demanding a specific key, rather than simply "press
any key"? Even better, key combination? Handle Ctrl-C by catching
KeyboardInterrupt and you can take advantage of Python's existing
cross-platform handling of the standard interrupt signal.
If Ctrl-C won't work for you, how about stipulating that it be Enter?
"Press Enter to quit" isn't too much worse than "Press any key to
quit" (plus you have less chance of accidentally terminating the
program when you don't want to). Spin off a thread to wait for enter.
I've tested this only on Linux, but it ought to work:
import threading
import time
shutdown = False
def wait_for_enter():
print("Hit Enter to quit.")
input()
global shutdown; shutdown = True
threading.Thread(target=wait_for_enter).start()
while "more work to do":
print("Getting data...")
time.sleep(1)
print("Saving data to file...")
time.sleep(1)
if shutdown:
print("Pre-termination...")
time.sleep(1)
raise SystemExit("exit")
If it doesn't, try switching around which is the secondary thread and
which is the primary - spin off a thread to do the work, then call
input() in the main thread.
ChrisA
--
https://mail.python.org/mailman/listinfo/python-list
Re: plot / graph connecting re ordered lists
On Tue, Jan 23, 2018 at 4:15 PM Dennis Lee Bieber wrote: > On Tue, 23 Jan 2018 13:51:55 -0700, Vincent Davis > declaimed the following: > > >Looking for suggestions. I have an ordered list of names these names will > >be reordered. I am looking to make a plot, graph, with the two origins of > > IE: you have two lists with the same items in different orders... > > >the names in separate columns and a line connecting them to visually > >represent how much they have moved in the reordering. > >Surely there is some great example code for this on the net an am not > >finding a clean example. > > > > Determine positions: > > pos = [] > for p, name in enumerate(first_list): > np = second_list.index(name) > pos.append( (name, p, np) ) > > for (name, p, np) in pos: > draw_line((1,p) , (2, np)) > label( (1, p), name) > > Exact details of graphics package and scaling left as an exercise Actualy, it’s recomendations for a graphing package And an example using it for such a graph that I am most interested in. I know how to relate the names on the 2 lists. > -- > Wulfraed Dennis Lee Bieber AF6VN > wlfr...@ix.netcom.comHTTP://wlfraed.home.netcom.com/ > > -- > https://mail.python.org/mailman/listinfo/python-list > -- Sent from mobile app. Vincent Davis 720-301-3003 -- https://mail.python.org/mailman/listinfo/python-list
Re: plot / graph connecting re ordered lists
On 23/01/18 23:42, Vincent Davis wrote: > On Tue, Jan 23, 2018 at 4:15 PM Dennis Lee Bieber > wrote: > >> On Tue, 23 Jan 2018 13:51:55 -0700, Vincent Davis >> declaimed the following: >> >>> Looking for suggestions. I have an ordered list of names these names will >>> be reordered. I am looking to make a plot, graph, with the two origins of >> >> IE: you have two lists with the same items in different orders... >> >>> the names in separate columns and a line connecting them to visually >>> represent how much they have moved in the reordering. >>> Surely there is some great example code for this on the net an am not >>> finding a clean example. >>> >> >> Determine positions: >> >> pos = [] >> for p, name in enumerate(first_list): >> np = second_list.index(name) >> pos.append( (name, p, np) ) >> >> for (name, p, np) in pos: >> draw_line((1,p) , (2, np)) >> label( (1, p), name) >> >> Exact details of graphics package and scaling left as an exercise > > > Actualy, it’s recomendations for a graphing package And an example using it > for such a graph that I am most interested in. I know how to relate the > names on the 2 lists. > > >> -- >> Wulfraed Dennis Lee Bieber AF6VN >> wlfr...@ix.netcom.comHTTP://wlfraed.home.netcom.com/ >> >> -- >> https://mail.python.org/mailman/listinfo/python-list >> Maybe http://graphviz.org/ and http://matthiaseisen.com/articles/graphviz/ Duncan -- https://mail.python.org/mailman/listinfo/python-list
Re: Processing a key pressed in Python 3.6
On Tue, Jan 23, 2018 at 11:29 PM, Virgil Stokes wrote: > > How would this code be modified to handle using the "Esc" key instead of the > "Enter" key? The input() function depends on the console or terminal to read a line of input. If you're using the Windows console, it calls the high-level ReadConsole (or ReadFile) function, which performs a 'cooked' read. In this case some keys are reserved. Escape is consumed to clear/flush the input buffer. Function keys and arrows are consumed for line editing and history navigation. And for some reason line-feed (^J) is always ignored. Additionally, normal operation requires the following input modes to be enabled: ENABLE_PROCESSED_INPUT process Ctrl+C as CTRL_C_EVENT and carriage return (^M) as carriage return plus line feed (CRLF). consume backspace (^H) to delete the previous character. ENABLE_LINE_INPUT return only when a carriage return is read. ENABLE_ECHO_INPUT echo read characters to the active screen. Reading the escape key from the console requires the low-level ReadConsoleInput, GetNumberOfConsoleInputEvents, and FlushConsoleInputBuffer functions. These access the console's raw stream of input event records, which includes key events, mouse events, and window/buffer resize events. It's a bit complicated to use this API, but fortunately the C runtime wraps it with convenient functions such as _kbhit, _getwch, and _getwche (w/ echo). On Windows only, you'll find these functions in the msvcrt module, but named without the leading underscore. Here's an example of reading the escape character without echo: >>> msvcrt.getwch() '\x1b' Simple, no? -- https://mail.python.org/mailman/listinfo/python-list
Re: Processing a key pressed in Python 3.6
On 2018-01-23 23:29, Virgil Stokes wrote:
Another follow-up question:
How would this code be modified to handle using the "Esc" key instead of
the "Enter" key?
This version uses msvcrt on Windows:
import msvcrt
import threading
import time
shutdown = False
def wait_for_enter():
global shutdown
print("Hit Enter to quit.")
# b'\x0D' is the bytestring produced by the Enter key.
# b'\x1B' is the bytestring produced by the Esc key.
if msvcrt.getch() == b'\x1B':
shutdown = True
threading.Thread(target=wait_for_enter).start()
while "more work to do":
print("Getting data...")
time.sleep(1)
print("Saving data to file...")
time.sleep(1)
if shutdown:
print("Pre-termination...")
time.sleep(1)
raise SystemExit("exit")
Another function of note is "msvcrt.kbhit()", which will tell you if
there's a key waiting to be read.
This is all in the docs for the msvcrt module.
On 2018-01-23 20:15, Chris Angelico wrote:
On Wed, Jan 24, 2018 at 5:50 AM, Virgil Stokes wrote:
I would appreciate help on finding a solution to following problem. This is
the general structure of the "problem" code:
while True
# Get some data from the web and process it
...
...
# Write these data to a file
...
...
# Check if a_key has been pressed in the command window
...
...
if a_key_pressed:
# Perform some pre-termination tasks
...
...
# Close the output data file
...
...
raise SystemExit('Exit')
I am running the code with Python 3.6 on a windows 10 platform. I have tried
many approaches (mainly those posted on stackoverflow) but I have yet to
find an approach that works for this structure.
Note:
1) The code is executed in the windows 10 command window
2) I am not using wxPython, IDLE, or pyGame in this application.
3) The time to get the data, process it and write it to a file can
take from 0.5 sec to 1.5 sec
4) The key hit need not be echoed to the command window
Are you okay with demanding a specific key, rather than simply "press
any key"? Even better, key combination? Handle Ctrl-C by catching
KeyboardInterrupt and you can take advantage of Python's existing
cross-platform handling of the standard interrupt signal.
If Ctrl-C won't work for you, how about stipulating that it be Enter?
"Press Enter to quit" isn't too much worse than "Press any key to
quit" (plus you have less chance of accidentally terminating the
program when you don't want to). Spin off a thread to wait for enter.
I've tested this only on Linux, but it ought to work:
import threading
import time
shutdown = False
def wait_for_enter():
print("Hit Enter to quit.")
input()
global shutdown; shutdown = True
threading.Thread(target=wait_for_enter).start()
while "more work to do":
print("Getting data...")
time.sleep(1)
print("Saving data to file...")
time.sleep(1)
if shutdown:
print("Pre-termination...")
time.sleep(1)
raise SystemExit("exit")
If it doesn't, try switching around which is the secondary thread and
which is the primary - spin off a thread to do the work, then call
input() in the main thread.
ChrisA
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Re: Processing a key pressed in Python 3.6
Ok Dennis,
You were correct. The following also works in the Windows 10 command window.
import time
import msvcrt
while "more work to do":
print("Getting data...")
time.sleep(1)
print("Saving data to file...")
time.sleep(1)
key = msvcrt.getwch()
#print('key: %s'%key) # just to show the result
if key == chr(27):
print("Pre-termination...")
time.sleep(1)
raise SystemExit("exit")
Note, I am using the "Esc" key to exit, which is one answer to my last
posting on this topic.
On 2018-01-23 20:37, Dennis Lee Bieber wrote:
On Tue, 23 Jan 2018 19:50:57 +0100, Virgil Stokes declaimed
the following:
I am running the code with Python 3.6 on a windows 10 platform. I have
tried many approaches (mainly those posted on stackoverflow) but I have
yet to find an approach that works for this structure.
Note:
1) The code is executed in the windows 10 command window
2) I am not using wxPython, IDLE, or pyGame in this application.
3) The time to get the data, process it and write it to a file can
take from 0.5 sec to 1.5 sec
4) The key hit need not be echoed to the command window
And none of your searching found
https://docs.python.org/3/library/msvcrt.html
which is part of the standard library (and documented in the library
manual). The module IS Windows specific, you'd have to rewrite the code to
run on Linux.
Now, if your requirement was to detect a keypress WHILE the data
fetch/processing was happening, the solution will be different.
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Re: Why is there no functional xml?
On Tuesday, January 23, 2018 at 8:23:43 PM UTC+5:30, Peter Otten wrote:
> Rustom Mody wrote:
> > [I find the OO/imperative style of making a half-done node and then
> > [throwing
> > piece-by-piece of contents in/at it highly aggravating]
>
> What I meant is that once you throw a bit of introspection at it much of the
> tedium vanishes. Here's what might become of the DOM-creation as part of an
> actual script:
«snipped named-tuple magic»
> To generalize that to handle arbitrarily nested lists and namedtuples a bit
> more effort is needed, but I can't see where lxml.objectify could make that
> much easier.
You really mean that??
Well sure in the programming world and even more so in the python world
“Flat is better than nested” is a maxim
But equally programmers need to satisfy requirements…
And right now I am seeing things like this
---
http://schemas.xmlsoap.org/soap/envelope/";>
http://example.com/";>
AGGREGATION_ANALYSIS
«Big base64 blob»
---
Thats 7 levels of nesting (assuming I can count right!)
Speaking of which another followup question:
With
# Read above xml
>>> with open('soap_response.xml') as f: inp = etree.parse(f)
# namespace dict
>>> nsd = {'soap': "http://schemas.xmlsoap.org/soap/envelope/";, 'locns':
>>> "http://example.com/"}
The following behavior is observed — actual responses elided in the interest of
brevity
>>> inp.xpath('//soap:Body', namespaces = nsd)
finds/reaches the node
>>> inp.xpath('//locns:blobRetrieveResponse', namespaces = nsd)
finds
>>> inp.xpath('//locns:dtCreationDate', namespaces = nsd)
does not find
>>> inp.xpath('//dtCreationDate', namespaces = nsd)
finds
>>> inp.xpath('//dtCreationDate')
also finds
Doesnt this contradict the fact that dtCreationDate is under the locns
namespace??
Any explanations??
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Re: python to C code generator
On Tue, 23 Jan 2018 17:43:18 +, bartc wrote: > It wouldn't be a satisfactory way of writing C programs. So, although > I'm not that big a fan of C syntax, it might be better to write C as C, > and Python as Python, to avoid confusion.) This. The fundamental reality is that `a + b` means different things in C and Python. Even if you limit yourself to integers and not arbitrary values (fractions, lists, strings, etc) the semantics are different: - in C, ints have a fixed number of bits and any addition which ends up out of range is undefined behaviour[1]; - while Python uses BigInts, overflow is impossible, and the only possible error is that you run out of memory and an exception is raised (although the addition can take an indefinite long amount of time). Often the difference doesn't matter... but when it does matter, it *really* matters. [1] If anyone thinks that it is addition with overflow, you are wrong. Some C compilers *may* use overflow, but the language strictly defines it as undefined behaviour, so the compiler can equally choose to set your computer on fire[2] if it prefers. https://blog.regehr.org/archives/213 [2] http://www.catb.org/jargon/html/H/HCF.html -- Steve -- https://mail.python.org/mailman/listinfo/python-list
