list findall python code example

Example 1: python find in list

# There is several possible ways if "finding" things in lists.
'Checking if something is inside'
3 in [1, 2, 3] # => True
'Filtering a collection'
matches = [x for x in lst if fulfills_some_condition(x)]
matches = filter(fulfills_some_condition, lst)
matches = (x for x in lst if x > 6)
'Finding the first occurrence'
next(x for x in lst if ...)
next((x for x in lst if ...), [default value])
'Finding the location of an item'
[1,2,3].index(2) # => 1
[1,2,3,2].index(2) # => 1
[1,2,3].index(4) # => ValueError
[i for i,x in enumerate([1,2,3,2]) if x==2] # => [1, 3]

Example 2: 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"