On Sep 2, 11:55 am, Steven D'Aprano <[EMAIL PROTECTED]
cybersource.com.au> wrote:
> I find myself writing command line tools in Python where I wish to
> include "verbose" output to stdout.
>
> I start with a helper function:
>
> def print_(obj, level=0):
> if _verbosity >= level:
> print obj
>
> And then I end up with functions or methods looking like this:
>
> def parrot(x)
> print_("precondition", level=2)
> do_something()
> print_("status is good...", level=1)
> print_("parrot is squawking strongly now", level=2)
> do_something_else()
> print_("squawk squawk squawk", level=3)
> do_more()
> print_("postcondition", level=1)
> return something
>
> That often means that my functions end up with more message printing code
> than actual code. The whole thing seems messy and hard to manage for all
> but the smallest scripts.
>
> Worst of all, sometimes the messages I wish to print may be expensive to
> compute, and I don't want to waste time computing them if they aren't
> going to be printed because the verbosity is too low. But nor do I wish
> to fill my code with this:
>
> if _verbosity >= 3:
> x = calculate_complicated_thing()
> print_(x, level=3)
>
> Is there a better way of doing this than the way I am going about it?
I do something like this, although I don't know if it would
be an improvement.
def collatz(a,p):
""" 3x+1 sequencer, no loop detection
collatz(a,p)
a: starting value
p: print options (binary)
bit 0 print even numbers (turns off power division)
bit 1 print odd numbers
bit 2 print debug (if any)
returns: CollatzSequenceParameters [R1count, R2count]
"""
ONE = gmpy.mpz(1)
TWO = gmpy.mpz(2)
TWE = gmpy.mpz(3)
a = gmpy.mpz(a)
t = 0
u = 0
done = 0
if (p & 1)==1:
print_evens = True
else:
print_evens = False
if (p & 2)==2:
print_odds = True
else:
print_odds = False
if (p & 4)==4:
print_debug = True
else:
print_debug = False
while done==0:
f = gmpy.scan1(a,0) # locate LS 1-bit
if f>0: # it's even
if print_evens:
print a,
a = a >> 1 # no power division
u += 1
else:
a = a >> f # power division
u += f
else:
if print_odds:
print a,
if a==1:
done = 1
seq_end = t + u
else:
a = a*TWE + ONE
t += 1
return [u,t]
>
> --
> Steven
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