Check if string has numbers, letters and spaces

Question

I'm trying to come up with an assert statement that checks whether a nonempty string, s, contains alphanumeric characters and spaces:

    assert s.isalnum()

I understand that this will return False if there are spaces because it checks that whether every character is either a letter or number. How do I fix this?

EDIT: For clarification, I'm trying to create an assert statement that checks whether a nonempty string contains alphanumeric characters and/or spaces. For example, " a 4 bc " and "ab" should both return True.

Answer 1

Maybe this is what you want:

assert any(substr.issapce() or substr.isdigit() or substr.isalpha() for substr in s)

Strings for testing:

>>> s1 = '123 45    abc  67  d'
>>> s2 = '123456'
>>> s3 = 'abcd'
>>> s4 = ':?--==++'

Check whether a string contains any space:

>>> def hasAnySpace(str):
...   return ' ' in str
...
>>> hasAnySpace(s1)
True
>>> hasAnySpace(s2)
False
>>> hasAnySpace(s3)
False
>>> hasAnySpace(s4)
False

Check whether a string contains any digit, you can use any function and str.isdigit function:

>>> def hasAnyDigit(str):
...   return any (substr.isdigit() for substr in str)
...
>>> hasAnyDigit(s1)
True
>>> hasAnyDigit(s2)
True
>>> hasAnyDigit(s3)
False
>>> hasAnyDigit(s4)
False

Check whether a string contains any alphabetic character, you can use any function and str.isalpha function:

>>> def hasAnyAlpha(str):
...   return any(substr.isalpha() for substr in str)
...
>>> hasAnyAlpha(s1)
True
>>> hasAnyAlpha(s2)
False
>>> hasAnyAlpha(s3)
True
>>> hasAnyAlpha(s4)
False

Check whether a string contains any number, or any alphabetic character or any space:

>>> def hasAnyAlNumSpace(str):
...   return any(substr.isalpha() or substr.isdigit() or substr.isspace() for substr in str)
...
>>> hasAnyAlNumSpace(s1)
True
>>> hasAnyAlNumSpace(s2)
True
>>> hasAnyAlNumSpace(s3)
True
>>> hasAnyAlNumSpace(s4)
False

If you want to use assert statement, you can use any combination of them:

>>> assert hasAnySpace(s1) or hasAnyDigit(s1) or hasAnyAlpha(s1) 
>>> assert hasAnySpace(s2) or hasAnyDigit(s2) or hasAnyAlpha(s2)
>>> assert hasAnySpace(s3) or hasAnyDigit(s3) or hasAnyAlpha(s3)
>>> assert hasAnySpace(s4) or hasAnyDigit(s4) or hasAnyAlpha(s4)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AssertionError
>>>
>>> assert hasAnySpace(s1)
>>> assert hasAnySpace(s2)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AssertionError
>>>
>>> assert hasAnyAlNumSpace(s1)
>>> assert hasAnyAlNumSpace(s2)
>>> assert hasAnyAlNumSpace(s3)
>>> assert hasAnyAlNumSpace(s4)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AssertionError

Of course, if you don't like these methods, you can simply use assert like this:

assert ' ' in s1    
assert any(substr.isdigit() for substr in s1)
assert any(substr.isalpha() for substr in s1)
assert (' ' in s1) or any(substr.isdigit() or substr.isalpha() for substr in s1)
assert any(substr.issapce() or substr.isdigit() or substr.isalpha() for substr in s1)