Hello coders, today we are going to solve Regex Substitutions HackerRank Solution in Python.
Objective
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.
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 81Replacements 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 commentOutput
<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
|| → orBoth && 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. Solution – Regex Substitution in Python
# Enter your code here. Read input from STDIN. Print output to STDOUT
import re
for _ in range(int(input())):
print(re.sub(r'(?<= )(&&|\|\|)(?= )', lambda x: 'and' if x.group() == '&&' else 'or', input()))
Disclaimer: The above Problem (Regex Substitution) is generated by Hacker Rank but the Solution is Provided by CodingBroz. This tutorial is only for Educational and Learning Purpose.