[FIXED] Python: how do I call `print` from `eval` in a loop?

Issue

When I call print from eval:

def printList(myList):
    maxDigits = len(str(len(myList)))
    Format = '0{0}d'.format(maxDigits)
    for i in myList:
        eval('print "#{0:' + Format + '}".format(i+1), myList[i]')

it gives an error:

    print "#{0:01d}".format(i+1), myList[i]
        ^
SyntaxError: invalid syntax

I tried to make use of this, and re-wrote it:

def printList(myList):
    maxDigits = len(str(len(myList)))
    Format = '0{0}d'.format(maxDigits)
    for i in myList:
        obj = compile(src, '', 'exec')
        eval('print "#{0:' + Format + '}".format(i+1), myList[i]')

but this complains about the i:

NameError: name 'i' is not defined

P.S. I'm dealing with python2.6

Solution

You don't need eval:

def printList(myList):
    maxDigits = len(str(len(myList)))
    str_format = '#{0:0' + str(maxDigits) + '}'
    for i, elem in enumerate(myList, 1):
        print str_format.format(i), elem

or, as @SvenMarnach noted, you can put even the formatting parameter into one format call:

def printList(myList):
    maxDigits = len(str(len(myList)))
    for i, elem in enumerate(myList, 1):
        print '#{1:0{0}} {2}'.format(maxDigits, i, elem)

Answered By - eumiro