Hello Programmers, In this post, you will know how to solve the Regex Substitution in Python HackerRank Solution. This problem is a part of the HackerRank Python Programming Series.
One more thing to add, don’t directly look for the solutions, first try to solve the problems of Hackerrank by yourself. If you find any difficulty after trying several times, then you can look for solutions.
Regex Substitution in Python HackerRank Solution
Problem
The re.sub() tool (sub stands for substitution) evaluates a pattern and, for each valid match, it calls a method (or lambda).
The method is called for all matches and can be used to modify strings in different ways.
The re.sub() method returns the modified string as an output.
Learn more about re.sub()
Transformation of Strings
Code :
import re
#Squaring numbers
def square(match):
number = int(match.group(0))
return str(number**2)
print re.sub(r"\d+", square, "1 2 3 4 5 6 7 8 9")
Output :
1 4 9 16 25 36 49 64 81
Replacements in Strings :
Code :
import re
html = """
<head>
<title>HTML</title>
</head>
<object type="application/x-flash"
data="your-file.swf"
width="0" height="0">
<!-- <param name="movie" value="your-file.swf" /> -->
<param name="quality" value="high"/>
</object>
"""
print re.sub("(<!--.*?-->)", "", html) #remove comment
Output :
<head> <title>HTML</title> </head> <object type="application/x-flash" data="your-file.swf" width="0" height="0"> <param name="quality" value="high"/> </object>
Task :
You are given a text of N lines. The text contains && and || symbols.
Your task is to modify those symbols to the following:
&& → and || → or
Both && and || should have a space ” ” on both sides.
Input Format :
The first line contains the integer, N.
The next N lines each contain a line of the text.
Constraints :
- 0 < N < 100
- Neither
&&nor||occur in the start or end of each line.
Output Format :
Output the modified text.
Sample Input :
11
a = 1;
b = input();
if a + b > 0 && a - b < 0:
start()
elif a*b > 10 || a/b < 1:
stop()
print set(list(a)) | set(list(b))
#Note do not change &&& or ||| or & or |
#Only change those '&&' which have space on both sides.
#Only change those '|| which have space on both sides.
Sample Output :
a = 1;
b = input();
if a + b > 0 and a - b < 0:
start()
elif a*b > 10 or a/b < 1:
stop()
print set(list(a)) | set(list(b))
#Note do not change &&& or ||| or & or |
#Only change those '&&' which have space on both sides.
#Only change those '|| which have space on both sides.Regex Substitution in Python HackerRank Solutions
import re
def change(match):
if match.group(1) == '&&':
return 'and'
else:
return 'or'
for _ in range(int(input())):
print(re.sub(r"(?<= )(\|\||&&)(?= )", change,input()))Disclaimer: The above Problem (Regex Substitution in Python) is generated by Hackerrank but the Solution is Provided by BrokenProgrammers. This tutorial is only for Educational and Learning purposes.
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