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Dumb python questions

Paul Rubin phr-n2001 at nightsong.com
Wed Aug 15 05:58:26 EDT 2001 
Richard Jones <richard at bizarsoftware.com.au> writes:
> It's right there in the second paragraph... 
> 
> '''Complex numbers have a real and imaginary part, which are both implemented 
> using double in C. To extract these parts from a complex number z, use z.real 
> and z.imag.'''

Oops, yes, there it is.  Thanks.  It's not in the table of operations
underneath and probably ought to be added.

> 
> > Here's another dumb question, about the for loop: if I want to add
> > up the first 100 numbers in the naive way, am I really supposed to say
> >
> >    sum = 0
> >    for i in range(101) :
> >      sum = sum + i
> >
> > and if I say that, will range(101) really malloc up and populate an
> > array of length 100? 
> 
> You could use xrange, which won't malloc the list.

xrange apparently doesn't malloc the values until they're used, but
they eventually get malloc'd.  I think functional programming has run
slightly amuck here.  What's wanted is something equivalent to

   sum = 0
   i = 1
   while i <= 100 :
      sum = sum + i
      i = i + 1

Python is really pleasant to code in and mostly well designed.  I just
keep hitting what seem like little lapses of common sense.

Here's another one: the print statement puts a gratuituous space after
each thing you print.  So

   for i in ['a','b','c']:
     print i,

prints "a b c " instead of "abc".
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