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
– Kevin, Commented Dec 3, 2014 at 13:04

Community · Accepted Answer · 2017-05-23 12:21:27Z

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, 2017 at 12:21

CommunityBot

11 silver badge

answered Dec 3, 2014 at 13:02

Cory Kramer

119k19 gold badges176 silver badges233 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Thomas · Accepted Answer · 2014-12-03 13:08:30Z

-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 3, 2014 at 13:08

Thomas

1304 bronze badges

Collectives™ on Stack Overflow

python string formatting using .format and variable

2 Answers 2

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related