python search string code example

Example 1: python regular expression

import re

# The string you want to find a pattern within
test_string = 'Hello greppers!'

# Creating a regular expression pattern
# This is a simple one which finds "Hello"
pattern = re.compile(r'Hello')

# This locates and returns all the occurences of the pattern
# within the test_string
match = pattern.finditer(test_string)

# Outputs all the ocurrences which were returned as 
# as match objects
for match in matches:
  print(match)

Example 2: find string in string python

>>> str = "Messi is the best soccer player"
>>> "soccer" in str
True
>>> "football" in str
False

Example 3: python .findall

## Search for pattern 'bb' in string 'aabbcc'.
  ## All of the pattern must match, but it may appear anywhere.
  ## On success, match.group() is matched text.
  match = re.search(r'bb', 'aabbcc') # found, match.group() == "bb"
  match = re.search(r'cd', 'aabbcc') # not found, match == None

  ## . = any char but \n
  match = re.search(r'...c', 'aabbcc') # found, match.group() == "abbc"

  ## \d = digit char, \w = word char
  match = re.search(r'\d\d\d', 'p123g') # found, match.group() == "123"
  match = re.search(r'\w\w\w', '@@abcd!!') # found, match.group() == "abc"

Example 4: find in python

def find_all_indexes(input_str, search_str):
    l1 = []
    length = len(input_str)
    index = 0
    while index < length:
        i = input_str.find(search_str, index)
        if i == -1:
            return l1
        l1.append(i)
        index = i + 1
    return l1


s = 'abaacdaa12aa2'
print(find_all_indexes(s, 'a'))
print(find_all_indexes(s, 'aa'))

Example 5: find on string in python

string.find(value, start, end)