Python: how do I use isnumeric()

Question

Can someone kindly explain why the following throws an exception? And what should I do with variable s to find out whether it contains a number?

s = str(10)
if s.isnumeric():
    print s

When I read Python documentation it seems to me the above should work. See:

But what I get is:

"AttributeError: 'str' object has no attribute 'isnumeric'"

Any help is most appreciated.

Thank you!

You could use [`isdigit()`](https://docs.python.org/2/library/stdtypes.html?highlight=isdigit#str.isdigit), if that helps. It's not exactly the same, but it's available in Python 2. — khelwood, Mar 07 '19 at 09:29
Possible duplicate of [AttributeError: 'str' object has no attribute 'isnumeric'](https://stackoverflow.com/questions/49263568/attributeerror-str-object-has-no-attribute-isnumeric). It would be beneficial if you gave more information about your problem, like the python version you're using. — Nexaspx, Mar 07 '19 at 09:33
Thanks everyone! I was using Python inside Google's appengine, and that turns out to be version 2.7 — MMazzon, Mar 07 '19 at 09:42

score 4 · Accepted Answer · answered Mar 07 '19 at 09:31

4

replace isnumeric() with isdigit() as

s = str(10)
if s.isdigit():
    print s

answered Mar 07 '19 at 09:31

programmer

@meowgoesthedog solution was specific to above example, where number is integer – programmer Mar 07 '19 at 09:36

score 2 · Answer 2 · answered Mar 07 '19 at 09:35

2

for python 2 isdigit() and for python 3 isnumeric()

python 2

s = str(10)
if s.isdigit():
    print s

python 3

 s = str(10)
 if s.isnumeric():
    print(s)

answered Mar 07 '19 at 09:35

bkawan

score 1 · Answer 3 · answered Mar 07 '19 at 09:34

1

You are obviously using python 2, so a such method does not exist.

That said, the most pythonic way would be to try to convert it

try:
    print(float(s))  # or int(s)
except ValueError:
    print("s must be numeric")

answered Mar 07 '19 at 09:34

blue_note

score 1 · Answer 4 · answered Mar 07 '19 at 09:39

1

Try using replace with isdigit:

print(s.replace('.', '').isdigit())

answered Mar 07 '19 at 09:39

U13-Forward

4 Answers4