Remove leading zeros from an IP address

Python Practice › String Programs › Program 73

Remove leading zeros from an IP address

EasyString Programs · 73 of 106

Write a Python program to remove leading zeros from each part of an IP address.

Input

"289.03.02.054"

Output

289.3.2.54

Approach

Split on dots, convert each part to int and back.

Solution

Python

ip = "289.03.02.054"print(".".join(str(int(part)) for part in ip.split(".")))

Output

289.3.2.54

Line by line

Line 2

int("054") is 54, which drops the zeros; int("0") stays 0.

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More string programs

#74EasyLongest run of zeros #75EasyRemove consecutive duplicates #76EasyCharacters that occur more than once #77EasyUncommon characters of two strings

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Sum of digits in a string

Python Practice › String Programs › Program 72

Sum of digits in a string

EasyString Programs · 72 of 106

Write a Python program to add up the digits in a string.

Input

"12sqatools78"

Output

Approach

Sum int(ch) for each digit character.

Solution

Python

print(sum(int(ch) for ch in "12sqatools78" if ch.isdigit()))

Output

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#73EasyRemove leading zeros from an IP address #74EasyLongest run of zeros #75EasyRemove consecutive duplicates #76EasyCharacters that occur more than once

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Capitalise the first and last letter of each word

Python Practice › String Programs › Program 71

Capitalise the first and last letter of each word

EasyString Programs · 71 of 106

Write a Python program to capitalise the first and last letters of each word.

Input

"this is my first program"

Output

ThiS IS MY FirsT PrograM

Approach

For each word: upper first + middle + upper last.

Solution

Python

def cap_ends(w):    if len(w) == 1:        return w.upper()    return w[0].upper() + w[1:-1] + w[-1].upper() print(" ".join(cap_ends(w) for w in "this is my first program".split()))

Output

ThiS IS MY FirsT PrograM

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#72EasySum of digits in a string #73EasyRemove leading zeros from an IP address #74EasyLongest run of zeros #75EasyRemove consecutive duplicates

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Remove all spaces

Python Practice › String Programs › Program 70

Remove all spaces

EasyString Programs · 70 of 106

Write a Python program to remove all spaces from a string.

Input

"python at sqatools"

Output

pythonatsqatools

Approach

replace(" ", "").

Solution

Python

print("python at sqatools".replace(" ", ""))

Output

pythonatsqatools

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#71EasyCapitalise the first and last letter of each word #72EasySum of digits in a string #73EasyRemove leading zeros from an IP address #74EasyLongest run of zeros

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Second most repeated word

Python Practice › String Programs › Program 69

Second most repeated word

EasyString Programs · 69 of 106

Write a Python program to find the second most repeated word.

Input

"ab bc ac ab bd ac nk hj ac"

Output

('ab', 2)

Approach

Counter.most_common() returns words sorted by count.

Solution

Python

from collections import Counterprint(Counter("ab bc ac ab bd ac nk hj ac".split()).most_common(2)[1])

Output

('ab', 2)

Line by line

Line 2

most_common(2) gives the top two pairs; index 1 is the second.

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#70EasyRemove all spaces #71EasyCapitalise the first and last letter of each word #72EasySum of digits in a string #73EasyRemove leading zeros from an IP address

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First repeated word

Python Practice › String Programs › Program 68

First repeated word

EasyString Programs · 68 of 106

Write a Python program to find the first word that repeats.

Input

"ab bc ca ab bd"

Output

ab

Approach

Remember words seen; return the first one seen again.

Solution

Python

def first_repeated(text):    seen = set()    for w in text.split():        if w in seen:            return w        seen.add(w)    return None print(first_repeated("ab bc ca ab bd"))

Output

ab

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#69EasySecond most repeated word #70EasyRemove all spaces #71EasyCapitalise the first and last letter of each word #72EasySum of digits in a string

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Split on the last delimiter

Python Practice › String Programs › Program 67

Split on the last delimiter

EasyString Programs · 67 of 106

Write a Python program to split a string on the last occurrence of a delimiter.

Input

"l,e,a,r,n,I,n,g,p,y,t,h,o,n"

Output

['l,e,a,r,n,I,n,g,p,y,t,h,o', 'n']

Approach

rsplit(",", 1) splits once, from the right.

Solution

Python

text = "l,e,a,r,n,I,n,g,p,y,t,h,o,n"print(text.rsplit(",", 1))

Output

['l,e,a,r,n,I,n,g,p,y,t,h,o', 'n']

Learn the concept

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Strings & Methods lesson → String Formatting & f-strings lesson →

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#68EasyFirst repeated word #69EasySecond most repeated word #70EasyRemove all spaces #71EasyCapitalise the first and last letter of each word

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Count and show vowels

Python Practice › String Programs › Program 66

Count and show vowels

EasyString Programs · 66 of 106

Write a Python program to count and display the vowels in a string.

Input

"welcome to Sqatools"

Output

['e', 'o', 'e', 'o', 'a', 'o', 'o'] 7

Approach

Collect the vowels in a list.

Solution

Python

text = "welcome to Sqatools"vowels = [ch for ch in text if ch.lower() in "aeiou"]print(vowels, len(vowels))

Output

['e', 'o', 'e', 'o', 'a', 'o', 'o'] 7

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#67EasySplit on the last delimiter #68EasyFirst repeated word #69EasySecond most repeated word #70EasyRemove all spaces

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Swap commas and dots

Python Practice › String Programs › Program 65

Swap commas and dots

EasyString Programs · 65 of 106

Write a Python program to swap commas and dots.

Input

"sqa,tools.python"

Output

sqa.tools,python

Approach

translate with a two-way mapping swaps them in one pass.

Solution

Python

text = "sqa,tools.python"print(text.translate(str.maketrans(",.", ".,")))

Output

sqa.tools,python

Line by line

Line 2

maketrans(",.", ".,") maps , to . and . to , at the same time; two replace calls would undo each other.

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More string programs

#66EasyCount and show vowels #67EasySplit on the last delimiter #68EasyFirst repeated word #69EasySecond most repeated word

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String to a list of words

Python Practice › String Programs › Program 64

String to a list of words

EasyString Programs · 64 of 106

Write a Python program to convert a string into a list of words.

Input

"learning python is fun"

Output

['learning', 'python', 'is', 'fun']

Approach

split().

Solution

Python

print("learning python is fun".split())

Output

['learning', 'python', 'is', 'fun']

Learn the concept

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Strings & Methods lesson → String Formatting & f-strings lesson →

More string programs

#65EasySwap commas and dots #66EasyCount and show vowels #67EasySplit on the last delimiter #68EasyFirst repeated word

← All 106 String Programs