Sort lines by length

Write a Python program to sort the lines of a file by their length.

x
short
medium line
a much longer line here

Approach

1. sorted(lines, key=len).

Solution

with open("story.txt", "w") as f:    f.write("medium line\nx\na much longer line here\nshort\n") with open("story.txt") as f:    lines = f.read().splitlines()for line in sorted(lines, key=len):    print(line)

x
short
medium line
a much longer line here

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Replace spaces with underscores

Write a Python program to replace every space in a file with an underscore.

learn_python_at_sqatools
file_handling_demo

Approach

1. Read, replace, write back.

Solution

with open("story.txt", "w") as f:    f.write("learn python at sqatools\nfile handling demo\n") with open("story.txt") as f:    text = f.read()with open("story.txt", "w") as f:    f.write(text.replace(" ", "_"))print(open("story.txt").read())

learn_python_at_sqatools
file_handling_demo

Line by line

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Words shorter than 5 characters

Write a Python program to display the words of a file that have fewer than 5 characters.

['is', 'a', 'very', 'good', 'tool', 'for', 'test']

Approach

1. Filter words by len(w) < 5.

Solution

with open("story.txt", "w") as f:    f.write("Python is a very good tool for test automation\n") with open("story.txt") as f:    print([w for w in f.read().split() if len(w) < 5])

['is', 'a', 'very', 'good', 'tool', 'for', 'test']

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Count consonants in a file

Write a Python program to count the consonants in a file.

16

Approach

1. Letters that are not vowels.

Solution

with open("story.txt", "w") as f:    f.write("Python file handling is easy\n") with open("story.txt") as f:    text = f.read().lower()print(sum(ch.isalpha() and ch not in "aeiou" for ch in text))

16

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Count vowels in a file

Write a Python program to count the vowels in a file.

8

Approach

1. Count characters in “aeiou” after lower-casing.

Solution

with open("story.txt", "w") as f:    f.write("Python file handling is easy\n") with open("story.txt") as f:    print(sum(ch in "aeiou" for ch in f.read().lower()))

8

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Read a file in reverse

Write a Python program to print the lines of a file in reverse order, and the whole text reversed.

third
second
first
driht
dnoces
tsrif

Approach

1. reversed(lines) for line order; [::-1] for characters.

Solution

with open("story.txt", "w") as f:    f.write("first\nsecond\nthird\n") with open("story.txt") as f:    lines = f.read().splitlines()for line in reversed(lines):    print(line)print("\n".join(lines)[::-1])

third
second
first
driht
dnoces
tsrif

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Move the cursor with seek()

Write a Python program to move the cursor to a specific position in a file.

Python
Hello

Approach

1. seek(n) moves to byte n; reading continues from there.

Solution

with open("story.txt", "w") as f:    f.write("Hello Python\n") with open("story.txt") as f:    f.seek(6)    print(f.read().strip())    f.seek(0)    print(f.read(5))

Python
Hello

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Cursor position with tell()

Write a Python program to find the current cursor position in a file.

0
5

Approach

1. tell() returns the position in bytes from the start.

Solution

with open("story.txt", "w") as f:    f.write("Hello Python\n") with open("story.txt") as f:    print(f.tell())    f.read(5)    print(f.tell())

0
5

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Count special characters in a file

Write a Python program to count special characters (not letters, digits or whitespace) in a file.

5

Approach

1. Count characters that are neither alphanumeric nor whitespace.

Solution

with open("story.txt", "w") as f:    f.write("Email: asha@sqatools.in! #python\n") with open("story.txt") as f:    print(sum(1 for ch in f.read() if not ch.isalnum() and not ch.isspace()))

5

Line by line

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Count digits in a file

Write a Python program to count the digits in a file.

12

Approach

1. sum(ch.isdigit() for ch in text).

Solution

with open("story.txt", "w") as f:    f.write("Order 4521 shipped on 2026-11-02\n") with open("story.txt") as f:    print(sum(ch.isdigit() for ch in f.read()))

12

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