re.MatchObject.span() Method in Python - regex

re.MatchObject.span() method returns a tuple containing starting and ending index of the matched string. If group did not contribute to the match it returns(-1,-1).

Syntax: re.MatchObject.span()

Parameters: group (optional) By default this is 0.

Return: A tuple containing starting and ending index of the matched string. If group did not contribute to the match it returns(-1,-1).

AttributeError: If a matching pattern is not found then it raises AttributeError.

Consider the below example:

Example 1:

# import library
import re

"""
We create a re.MatchObject and 
store it in  match_object variable, 
'()' parenthesis are used to define a 
specific group
"""
match_object = re.match(r'(\d+)',
                        '128935')

""" 
d in above pattern stands for numerical character
+ is used to match a consecutive set of characters 
satisfying a given condition so d+ will match a
consecutive set of numerical characters
"""

# generating the tuple with the 
# starting and ending index
print(match_object.span())

Output:

(0, 6)    

It's time to understand the above program. We use a re.match() method to find a match in the given string('128935') the 'd' indicates that we are searching for a numerical character and the '+' indicates that we are searching for continuous numerical characters in the given string. Note the use of '()' the parenthesis is used to define different subgroups.

Example 2: If a match object is not found then it raises AttributeError.

# import library
import re

"""
We create a re.MatchObject and 
store it in match_object variable,
'()' parenthesis are used to define a 
specific group"""
   
match_object = re.match(r'(\d+)',
                        'geeks')

""" 
d in above pattern stands for numerical character
+ is used to match a consecutive set of characters 
 satisfying a given condition so d+ will match a
consecutive set of numerical characters
"""

# generating the tuple with the
# starting and ending index
print(match_object.span())

Output:

Traceback (most recent call last):
  File "/home/18a058de83529572f8d50dc9f8bbd34b.py", line 17, in 
    print(match_object.span())
AttributeError: 'NoneType' object has no attribute 'span'