In the process of learning Python, you will always find that Python can easily solve many problems. Some complex tasks can even be done with a single line of Python code.
Here are 25 interesting Python codes, all of which are practical. I hope you can find they are useful.
1. Letter Anagram
If two words contain the same letters and are in a different order, they are called anagrams. For example, “silent” and “listen” are letter anagrams, while “apple” and “aplee” are not.
from collections import Counter
s1 = 'below'
s2 = 'elbow'
print('anagram') if Counter(s1) == Counter(s2) else print('not an anagram')
2. Binary to Decimal
decimal = int('1010', 2)
print(decimal) #10
3. Convert String to Lowercase
print("Hi my name is Tony Xu".lower())
# 'hi my name is tony xu'
print("Hi my name is Tony Xu".casefold())
# 'hi my name is tony xu'
4. Convert String to Uppercase
print("hi my name is Tony Xu".upper())
# 'HI MY NAME IS Tony Xu'
5. Convert String to Bytes
print("convert string to bytes using encode method".encode())
# b'convert string to bytes using encode method'
6. Copy File
import shutil
shutil.copyfile('source.txt', 'dest.txt')
7. Quick Sort
qsort = lambda l: l if len(l) <= 1 else qsort([x for x in l[1:] if x < l[0]]) + [l[0]] + qsort([x for x in l[1:] if x >= l[0]])
print(qsort([17, 29, 11, 97, 103, 5]))
# [5, 11, 17, 29, 97, 103]
8. Sum of N Numbers
n = 10
print((lambda x: (x*(x+1))/2)(n)
# 55
9. Switch the Value of Two Variables
a, b = b, a
10. Fibonacci
fib = lambda x: x if x<=1 else fib(x-1) + fib(x-2)
print(fib(20))
# 6765
11. Combine Nested Lists into One List
main_list = [[0, 1, 2], [11, 12, 13], [52, 53, 54]]
result = [item for sublist in main_list for item in sublist]
print(result)
>
[0, 1, 2, 11, 12, 13, 52, 53, 54]
12. Run an HTTP Server
python3 -m http.server 8000
python2 -m SimpleHTTPServer
13. Reverse a List
numbers = [0, 1, 2, 11, 12, 13, 52, 53, 54]
print(numbers[::-1])
# [54, 53, 52, 13, 12, 11, 2, 1, 0]
14. Factorial
import math
fact_5 = math.factorial(5)
print(fact_5)
# 120
15. Use for and if in List Comprehensions
even_list = [number for number in [1, 2, 3, 4] if number % 2 == 0]
print(even_list)
# [2, 4]
16. The Longest String in List
words = ['This', 'is', 'a', 'list', 'of', 'words']
result = max(words, key=len)
print(result)
# 'words'
17. List Comprehension
li = [num for num in range(0, 10)]
print(li)
# [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
18. Set Comprehension
num_set = {num for num in range(0, 10)}
print(num_set)
# {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
19. Dict Comprehension
dict_numbers = {x: x*x for x in range(1, 5)}
print(dict_numbers)
# {1: 1, 2: 4, 3: 9, 4: 16}
21. Print with if and else
print("even") if 4 % 2==0 else print("odd")
22. Infinite Loop
while 1:0
23. Check Data Type
print(isinstance(2, int))
# True
print(isinstance("allwin", str))
# True
print(isinstance([3, 4, 1997], list))
# True
24. Print to File
print("Hello, World!", file=open('file.txt', 'w'))
25. Frequency of a Character in a String
print("umbrella".count('l'))
# 2
And there you have it. Thank you for reading.
