python string formatting using .format and variable

Question

s1 = "cats"

print "are 10 cats {}" .format(s1*10) 
print "are 10 cats {10cats}" .format(10cats=s1*10)

First print works, second I get SyntaxError: invalid syntax. Why?

It's kind of weird to have numbers in your variable names at all. What if your boss comes in tomorrow and says "good job on the cat project, but we need to increase max cat-capacity from 10 to 20". Now you have to replace your `_10cats` variable everywhere with `_20cats`. — Kevin, Dec 03 '14 at 13:04

score 4 · Accepted Answer · edited May 23 '17 at 12:21

4

Variable names in python (and many other languages) cannot start with numbers. If you used a legal variable name, the second would work fine.

>>> s1 = "cats"
>>> print("are 10 cats {cats}" .format(cats=s1*10))
are 10 cats catscatscatscatscatscatscatscatscatscats

edited May 23 '17 at 12:21

Community

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answered Dec 03 '14 at 13:02

Cory Kramer

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score -1 · Answer 2 · answered Dec 03 '14 at 13:08

-1

As stated already, variable names in Python cannot start with numbers. Additionally, there are other characters that cannot be used in variable names in Python.

http://www.pasteur.fr/formation/infobio/python/ch02s03.html

answered Dec 03 '14 at 13:08

Thomas

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python string formatting using .format and variable

2 Answers2