How can I check if a string represents an int, without using try/except?

Question

Is there any way to tell whether a string represents an integer (e.g., \'3\', \'-17\' but not \'3.14\' or \'asf

Answer 1

str.isdigit() should do the trick.

Examples:

str.isdigit("23") ## True
str.isdigit("abc") ## False
str.isdigit("23.4") ## False

EDIT: As @BuzzMoschetti pointed out, this way will fail for minus number (e.g, "-23"). In case your input_num can be less than 0, use re.sub(regex_search,regex_replace,contents) before applying str.isdigit(). For example:

import re
input_num = "-23"
input_num = re.sub("^-", "", input_num) ## "^" indicates to remove the first "-" only
str.isdigit(input_num) ## True