Does Python Have a String 'Contains' Substring Method

Does Python have a string 'contains' substring method?

Use the in operator:

if "blah" not in somestring: 
    continue

Does Python have a string contains how many substring method, allowing for overlap?

Strings have a method count

You can do

s = '12212'

s.count('12') # this equals 2

Edited for the changing question, the answer below was posted as a comment by tobias_k

To count with overlap,

count_all = lambda string, sub: sum(string[i:i+len(sub)] == sub for i in range(len(string) - len(sub) + 1))

This can be called with,

count_all('1111', '11') # this returns 3

How to see if a string ONLY contains a substring in python

No regex necessary. Relying on the fact that str.count counts non-overlapping occurrences

len(target) * data.count(target) == len(data)

Simple string methods are 400-800% faster than regex here:

>>> import re
>>> target = "World"
>>> data = "World" * 3
>>> pattern = f"^({re.escape(target)})+$"
>>> %timeit len(target) * data.count(target) == len(data)
115 ns ± 0.352 ns per loop (mean ± std. dev. of 7 runs, 10,000,000 loops each)
>>> %timeit re.match(pattern, data) is not None
456 ns ± 2.88 ns per loop (mean ± std. dev. of 7 runs, 1,000,000 loops each)
>>> %timeit bool(data.replace(target, ''))  # str.replace is faster again
51.7 ns ± 0.269 ns per loop (mean ± std. dev. of 7 runs, 10,000,000 loops each)

Check if a list of string contains particular letter or charcater in it(python)

lst = ['Mangos*','apples','REd']
for l in lst:
    if 'M' in l or '*' in l:
             print(l)

How do I check if a given Python string is a substring of another one?

Try using in like this:

>>> x = 'hello'
>>> y = 'll'
>>> y in x
True

Get string from list if that string contains substring

Use next(..) with a generator. This will sort of break the moment it finds the first instance. Of course, this is assuming one element definitely exists in your list.

def f(l, sub):
    return next(x for x in l if sub in x)

How to check if string includes substring with an unknown character in Python?

re.findall returns a list of all matches of a regex (docs.python.org/3/howto/regex.html) pattern in a string. The regex character . matches any character, but not a newline.

import re

txt = "foobar"

x = re.findall("oo.ar", txt) # -> ['oobar']
y = re.findall("ooba.", txt) # -> ['oobar']
print(x)
print(y)

Determining if a string contains a word

words = 'blue yellow'

if 'blue' in words:
    print 'yes'
else:
    print 'no'

Edit

I just realized that nightly blues would contain blue, but not as a whole word. If this is not what you want, split the wordlist:

if 'blue' in words.split():
    …

Check if a string contains substring or part of it

A more common task would be to find the longest common subsequence, but if you really are trying to do what you say in your question:

check if a string contains a substring or part of this substring.

Consider that this reduces to the following: At least one character must be in both strings.

This is trivial if you convert to a set and find the intersection:

>>> string = "Hello 13 World"
>>> substring = "01234567890"
>>> bool(set(string) & set(substring))
True
>>> string = 'Hello 13 world'
>>> substring = 'abc'
>>> bool(set(string) & set(substring))
False

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