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How to match at the beginning of string in python using Regular Expression?

PythonServer Side ProgrammingProgramming

A regular expression in Python is a group of characters that allows you to use a search pattern to find a string or set of strings. RegEx is a term for regular expressions.

To work with regular expressions in Python, utilise the re package.

To match with the beginning of the string in python by using regular expression, we use ^/w+ regular expression.

Here,

  • ^ implies the start with.
  • /w returns a match where the string contains any word characters (a z, A Z, 0 9, and underscore character).
  • + indicates one or more occurrence of a character.

Using re.search() method

In the following example code, we match the word tutorialspoint which is present at the beginning of the string ‘tutorialspoint is a great platform to enhance your skills’.

We begin by importing regular expression module.

import re

Then, we have used search() function which is imported from the re module to get the required string. This re.search() function in Python searches the string for a match and returns a match object if there is any match. The group() method is used to return the part of the string that is matched.

Example

import re
s = 'tutorialspoint is a great platform to enhance your skills'
result = re.search(r'^\w+', s)
print (result.group())

Output

The following output is obtained on executing the above program.

tutorialspoint

Example 2

Now, let us find out the first letter of a single string using re.search() method in Python −

import re
s = 'Program'
result = re.search(r"\b[a-zA-Z]", s)
print ('The first letter of the given string is:',result.group())

Output

The first letter of the given string is: P

Using re.findall() method

The method findall(pattern, string) in Python locates every occurrence of the pattern within the string. The caret (^) guarantees that you only match the word Python at the beginning of the string when you use the pattern “^\w+”

Example

import re
text = 'tutorialspoint is a great platform to enhance your skills in tutorialspoint'
result = re.findall(r'^\w+', text)
print(result)

Output

The substring ‘tutorialspoint’ appears twice, but there is only one place in the string where it matches which is at the beginning as seen in the output below −

['tutorialspoint']

Example

Now, let us find out the first letter of a single string using re.findall() method in Python −

import re
s = 'Program'
result = re.findall(r"\b[a-zA-Z]", s)
print ('The first letter of the given string is:',result)

Output

The first letter of the given string is: ['P']
raja
Pranav Indukuri
Updated on 08-Nov-2022 10:56:52

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