Easy questions from a python beginner

[Duncan Booth]

wheres pythonmonks <wherespythonmonks at gmail.com> wrote:

> I'm an old Perl-hacker, and am trying to Dive in Python.  I have some
> easy issues (Python 2.6)
> which probably can be answered in two seconds:
> 
> 1.  Why is it that I cannot use print in booleans??  e.g.:
>>>> True and print "It is true!"
> 
> I found a nice work-around using
> eval(compile(.....,"<string>","exec"))... Seems ugly to this Perl
> Programmer -- certainly Python has something better? 

In Python 2.x print is a statement. If you really wanted you could do:

   True and sys.write("It is true!\n")

In Python 3 you can do this:

   True and print("It is true!")

though I can't think of any situations where this would be better that just 
writing:

   if somecondition: print "whatever"

> 
> 2.  How can I write a function, "def swap(x,y):..." so that "x = 3; y
>= 7; swap(x,y);" given x=7,y=3??

Why use a function?

   x, y = y, x

> (I want to use Perl's Ref "\" operator, or C's &).
> (And if I cannot do this [other than creating an Int class], is this
> behavior limited to strings,
>  tuples, and numbers)

If you want to use perl's operators I suggest you use perl.

> 
> 3.  Why might one want to store "strings" as "objects" in numpy
> arrays?  (Maybe they wouldn't)?

Why would one want to write incomprehensible questions?

> 
> 4.  Is there a way for me to make some function-definitions explicitly
> module-local?
> (Actually related to Q3 below: Is there a way to create an anonymous
> scope?) 

Not really.

> 
> 5. Is there a way for me to introduce a indention-scoped variables in
> python? See for example: http://evanjones.ca/python-pitfall-scope.html

No. The page you reference effectively says 'my brain is used to the way 
Java works'. *My* brain is used to the way Python works. Who is to say 
which is better?

> 
> 6.  Is there a Python Checker that enforces Strunk and White and is
> bad English grammar anti-python?  (Only half joking)
> http://www.python.org/dev/peps/pep-0008/
> 
pylint will do quite a good job of picking over your code. Most people 
don't bother.