finding strings in a list of strings

Question

I have a python list ['100', '20.0', '?', 'a', '0']. The list contains real strings '?', 'a' and ints and floats coded in strings. I am trying to find the (real) strings '?', 'a' in the list.

You want to check if the value is an alphanumeric character? — HamzaMushtaq, Jul 08 '19 at 09:33
What about strings `nan`, `-inf` etc.? They are valid floats in Python — Andrej Kesely, Jul 08 '19 at 09:35
Try to parse each element, catch errors and save those "invalid" values as your "real strings" — h4z3, Jul 08 '19 at 09:36
Yes I am trying to find all the elements (including nan and inf) that are not floats — kosa, Jul 08 '19 at 09:37
You have some useful answers and discussions on this topic in this question: https://stackoverflow.com/questions/354038/how-do-i-check-if-a-string-is-a-number-float — locke14, Jul 08 '19 at 09:37
@locke14, Thankyou. This is what I am looking for. I can simply use `try` and `except`. — kosa, Jul 08 '19 at 09:39

score 2 · Accepted Answer · answered Jul 08 '19 at 09:37

data = ['100', '20.0', '?', 'a', '0']

result = []
for item in data:
    if not any(c.isnumeric() for c in item): # check if number exist in string
        result.append(item)
print (result)

output:

['?', 'a']

what is equal to list comprehension:

print ([item for item in data if not any(c.isnumeric() for c in item) ])

output:

['?', 'a']

finding strings in a list of strings

1 Answers1