Python: Print a variable’s name and value?

When debugging, we often see print statements like these:

print x        # easy to type, but no context
print 'x=',x   # more context, harder to type
12
x= 12

How can write a function that will take a variable or name of a variable and print its name and value? I’m interested exclusively in debugging output, this won’t be incorporated into production code.

debugPrint(x)    #  or
debugPrint('x')
x=12

Answer

You can just use eval:

def debug(variable):
    print variable, '=', repr(eval(variable))

Or more generally (which actually works in the context of the calling function and doesn’t break on debug('variable'), but only on CPython):

from __future__ import print_function

import sys

def debug(expression):
    frame = sys._getframe(1)

    print(expression, '=', repr(eval(expression, frame.f_globals, frame.f_locals)))

And you can do:

>>> x = 1
>>> debug('x + 1')
x + 1 = 2