How can I remove the single quotes from a string and use it for division in Python?

Question

How can I remove ' from the string '/' and use it for division in Python?

For example:

a='/'
b=6
c=3

bac

The answer should be 2.

the original is one string? "`a='/' b=6 c=3" ? And you want to break that up and do a calculation with it? — KobeJohn, Feb 13 '12 at 01:03
Are you trying to write a [parser](http://en.wikipedia.org/wiki/Parser)? Or something else? It's hard to see what you're trying to accomplish. — sarnold, Feb 13 '12 at 01:04
no its 3 separate variables i'm talking about the '/' specifically — Alex Demonaco, Feb 13 '12 at 01:05

score 6 · Answer 1 · answered Feb 13 '12 at 01:04

You can get the built-in operators as functions from the operator module:

import operator

a = operator.div
b = 6
c = 3

print a(b, c)

If you want to get the correct operator by the symbol, build a dict out of them:

ops = {
    "/": operator.div,
    "*": operator.mul,
    # et cetera
}

a = ops["/"]

score 4 · Accepted Answer · answered Feb 13 '12 at 01:04

Python has an eval() function that can do this:

a = "/"
b = "6"
c = "3"
print eval(b + a + c)

However, please note that if you're getting input from a remote source (like over a network), then passing such code to eval() is potentially very dangerous. It would allow network users to execute arbitrary code on your server.

score 3 · Answer 3 · edited May 23 '17 at 12:33

There are no single quotes in the variable a. Python just uses these to denote a represents a string. b and c represent ints and don't have the single quotes. If you ensure all of these variables are strings, you can join() them together:

>>> a='/'
>>> b=6
>>> c=3
>>> bac = ''.join(str(x) for x in (b, a, c))
>>> bac
'6/3'

See how there are single quotes at the beginning and end of the string.

You could then use eval() (with caution) to perform the division:

>>> eval(bac)
2

Related: Is using eval in Python a bad practice?

How can I remove the single quotes from a string and use it for division in Python?

3 Answers3