Python 유저를 위한 유용한 문법 자료 공유 (One-Liner For Loop)

[sinb57]

https://betterprogramming.pub/4-ways-to-write-one-liner-for-loops-in-python-e8c1db903ce2

In Python, you can turn your for loops into one-liners by using comprehensions.

1. List Comprehensions

numbers = [4, -2, 7, -4, 19]
new_nums = []
for num in numbers:
    if num > 0:
        new_nums.append(num)
print(new_nums)

new_nums = [num for num in numbers if num > 0]
print(new_nums)

2. Dictionary Comprehensions

• Example 1: Create a dictionary from a list

  nums = [10, 20, 30, 40, 50]
  dict = {}
  for num in nums:
      if num % 2 == 0:
          dict[num] = str(num)
      
  print(dict)

  dict = {num: str(num) for num in nums if num % 2 == 0}
  print(dict)

• Example 2: Operating on an existing dictionary

  data = {'a': 1, 'b': 2, 'c': 3, 'd': 4, 'e': 5}
  squared = {k:v*v for (k,v) in data.items()}
  print(squared)

  { key:value for (key,value) in dict if condition }

3. Set Comprehensions

numbers = [13, 21, 14, 24, 53, 62] 
  
filtered_nums = set() 
  
for num in numbers: 
    if num % 2 == 0: 
        filtered_nums.add(num) 
  
print(filtered_nums)

filtered_nums = {num for num in numbers if num % 2 == 0}
print(filtered_nums)

4. Generator Comprehensions

def square_even(numbers):
    for number in numbers:
        if number % 2 == 0:
            yield(number * number)
            
numbers = [1, 2, 3, 4, 5, 6]
squared_numbers = square_even(numbers)

for number in squared_numbers:
    print(number)

squared_numbers = (num * num for num in numbers if num % 2 == 0)
for number in squared_numbers: 
    print(number)