Summary: To match a pattern in a given text using only a single line of Python code, use the one-liner import re; print(re.findall(pattern, text)) that imports the regular expression library re and prints the result of the findall() function to the shell.
Problem: Given a string and a regular expression pattern. Match the string for the regex pattern—in a single line of Python code!
Example: Consider the following example that matches the pattern 'F.*r' against the string 'Learn Python with Finxter'.
import re s = 'Learn Python with Finxter' p = 'F.*r' # Found Match of p in s: 'Finxter'
Let’s dive into the different ways of writing this into a single line of Python code!
Exercise: Run the code. What’s the output of each method? Why does the output differ?
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Method 1: findall()
The re.findall(pattern, string, flags=0) method returns a list of string matches. Read more in our blog tutorial.
# Method 1: findall()
import re; print(re.findall('F.*r', 'Learn Python with Finxter'))
# ['Finxter']There’s no better way of importing the re library and calling the re.findall() function in a single line of code—you must use the semicolon A;B to separate the statements A and B.
The findall() function finds all occurrences of the pattern in the string.
Method 2: search()
The re.search(pattern, string, flags=0) method returns a match object of the first match. Read more in our blog tutorial.
# Method 2: search()
import re; print(re.search('F.*r', 'Learn Python with Finxter'))
# <re.Match object; span=(18, 25), match='Finxter'>The search() function finds the first match of the pattern in the string and returns a matching object
Method 3: match()
The re.match(pattern, string, flags=0) method returns a match object if the regex matches at the beginning of the string. Read more in our blog tutorial.
# Method 3: match()
import re; print(re.match('.*F.*r', 'Learn Python with Finxter'))
# <re.Match object; span=(0, 25), match='Learn Python with Finxter'>The match() function finds the match of the pattern at the beginning of the string and returns a matching object. In this case, the whole string matches, so the match object encloses the whole string.
Method 4: fullmatch()
The re.fullmatch(pattern, string, flags=0) method returns a match object if the regex matches the whole string. Read more in our blog tutorial.
# Method 4: fullmatch()
import re; print(re.fullmatch('.*F.*r.*', 'Learn Python with Finxter'))
#<re.Match object; span=(0, 25), match='Learn Python with Finxter'>The fullmatch() function attempts to match the whole string and returns a matching object if successful. In this case, the whole string matches, so the match object encloses the whole string.
Where to Go From Here?
Enough theory. Let’s get some practice!
Coders get paid six figures and more because they can solve problems more effectively using machine intelligence and automation.
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You build high-value coding skills by working on practical coding projects!
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