inshu chauhan wrote:
> On Fri, Apr 26, 2013 at 2:39 PM, Peter Otten <__pete...@web.de> wrote:
>
>> inshu chauhan wrote:
>>
>> > I have this part of my code where I am trying to traverse over an image
>> by
>> > running a for loop for both x and y co-ordinate axis. But the loop is
>> > terminating by just reading first pixel. Can think of a reason why this
>> is
>> > happening ?
>> >
>> > The code is:
>> > for sy in xrange(0, segimage.height):
>> > for sx in xrange(0, segimage.width):
>> > if segimage[sy,sx] == (0.0, 0.0, 0.0):
>> > continue
>> > else:
>> > seg_color = segimage[sy,sx]
>> > blue = int(seg_color[0])
>> > green = int(seg_color[1])
>> > red = int(seg_color[2])
>> > reg_num = blue + 256 * green + 65536 * red
>> > for l in f:
>> > sp = l.split(",")
>> > if len(sp) == 14:
>> > print sy, sx # for checking which pixel its
>> > reading currently
>> > print reg_num, sp[0] # for checking whats
>> > happening
>> > if reg_num == int(sp[0].strip()):
>> > print reg_num, sp[0].strip() # for checking
>> > whats happening
>> > classification = int(sp[13].strip())
>> >
>> >
>> > The inside "for loop" is for reading a csv format file from which I am
>> > extracting some information.
>>
>> My crystal ball says that the 'for sy...' and 'for sx...' loops are
>> running to completion, but you don't get the coordinates printed because
>> you put them into the 'for l in f' loop which will only run once.
>>
>
> Is there any means by which I can run this 'For l in f' loop again and
> again ?
>
>>
>> The quick and dirty fix is to replace
>>
>> f = open(...)
>>
>> in the code you are not showing with
>>
>> f == list(open(...))
>>
>
> f is just a text file(csv format).. so why list ??
Can you figure it out yourself from the following?
>>> f = open("tmp.data")
>>> for i in range(3):
... for line in f: print repr(line)
...
'alpha\n'
'beta\n'
'gamma\n'
>>> f = list(open("tmp.data"))
>>> for i in range(3):
... for line in f: print repr(line)
...
'alpha\n'
'beta\n'
'gamma\n'
'alpha\n'
'beta\n'
'gamma\n'
'alpha\n'
'beta\n'
'gamma\n'
>> The reasonable thing to do is of course to move the preprocessing (e.g.
>> csv-
>> parsing) out of the sy and sx loops.
>>
>
> I did this but again then what I intend to do is not really happening, For
> every pixel I read, I want to traverse the full file, so that the
> information I am taking from pixel have to match in one of the line in the
> file. Can this be done by modifying my code ? or something new has to be
> devised ?
I think I have already answered this, but here's another alternative:
>>> f = open("tmp.data")
>>> for i in range(3):
... f.seek(0)
... for line in f: print(repr(line))
...
'alpha\n'
'beta\n'
'gamma\n'
'alpha\n'
'beta\n'
'gamma\n'
'alpha\n'
'beta\n'
'gamma\n'
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