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Python practice problems help beginners to become experts in a python programming language with a small amount of practice effort.
Write a Python program to find the sum of the first and last digits of a number.
74351
7 + 1 = 8
n = 74351last = n % 10first = nwhile first >= 10: first //= 10print(first, "+", last, "=", first + last)7 + 1 = 8
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Write a Python program to find the first and last digits of a number.
74351
First digit: 7 Last digit: 1
n % 10; remove digits until one is left for the first digit.n = 74351last = n % 10first = nwhile first >= 10: first //= 10print("First digit:", first)print("Last digit:", last)First digit: 7 Last digit: 1
Keep dropping the last digit until a single digit remains.
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Write a Python program to count the digits of a number.
908172
Digits: 6
n = 908172count = 0while n > 0: n //= 10 count += 1print("Digits:", count)Digits: 6
Each //= 10 removes one digit.
len(str(abs(n))) gives the same answer for non-zero numbers.
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Write a Python program to find the sum of all odd numbers from 1 to n.
n = 20
Sum of odd numbers: 100
n = 20total = 0for i in range(1, n + 1, 2): total += iprint("Sum of odd numbers:", total)Sum of odd numbers: 100
The sum of the first k odd numbers is k², so for n = 20 (ten odd numbers) the answer is 100.
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Write a Python program to find the sum of all even numbers from 1 to n.
n = 20
Sum of even numbers: 110
n = 20total = 0for i in range(2, n + 1, 2): total += iprint("Sum of even numbers:", total)Sum of even numbers: 110
The step of 2 skips odd numbers entirely.
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Write a Python program to find the sum of all natural numbers from 1 to n.
n = 50
1275 | formula: 1275
n = 50total = 0for i in range(1, n + 1): total += iprint(total, "| formula:", n * (n + 1) // 2)1275 | formula: 1275
The formula n(n+1)/2 confirms the loop’s answer.
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Write a Python program to print all odd numbers from 1 to 100.
[1, 3, 5, 7, 9] ... [95, 97, 99] 50 odd numbers
range(1, 100, 2).odds = [n for n in range(1, 101) if n % 2 == 1]print(odds[:5], "...", odds[-3:])print(len(odds), "odd numbers")[1, 3, 5, 7, 9] ... [95, 97, 99] 50 odd numbers
The comprehension keeps numbers whose remainder after dividing by 2 is 1.
Printing only the first and last few keeps the output short.
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Write a Python program to print all even numbers from 1 to 100.
2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100
range(2, 101, 2).for n in range(2, 101, 2): print(n, end=" ")print()2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100
Starting at 2 with a step of 2 visits only even numbers.
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Write a Python program to print the alphabet from A to Z using a for loop and chr() (chr(65) is ‘A’).
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 97 -> abcdefghijklmnopqrstuvwxyz
chr().for code in range(65, 91): print(chr(code), end=" ")print()print(ord("a"), "->", "".join(chr(c) for c in range(ord("a"), ord("z") + 1)))A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 97 -> abcdefghijklmnopqrstuvwxyz
65 is the Unicode code of ‘A’ and 90 of ‘Z’.
ord() is the reverse of chr(); this line builds a to z without remembering the numbers.
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Write a Python program to print the natural numbers from n down to 1 using a while loop.
n = 10
10 9 8 7 6 5 4 3 2 1
n = 10while n >= 1: print(n, end=" ") n -= 1print()10 9 8 7 6 5 4 3 2 1
-= 1 counts down.
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