Python: Test if value can be converted to an int in a list comprehension

If you only deal with integers, you can use str.isdigit():

Return true if all characters in the string are digits and there is at least one character, false otherwise.

[row for row in listOfLists if row[x].isdigit()]

Or if negative integers are possible (but should be allowed):

row[x].lstrip('-').isdigit()

And of course this all works only if there are no leading or trailing whitespace characters (which could be stripped as well).

types casting int python

What about using a regular expression? (use re.compile if needed):

import re...return [row for row in listOfLists if re.match("-?\d+$", row[x])]

types casting int python

return filter(lambda y: y[x].isdigit(), listOfLists)

or if you need to accept negative integers

return filter(lambda y: y[x].lstrip('-').isdigit(), listOfLists)

As fun as list comprehension is, I find it less clear in this case.

CodeHunter