python-新手上路-Day10 ｜ List Comprehension
在 Python 中，有一種稱為「List Comprehension」的技巧，可以讓你以一行簡潔的方式創建新的 List。這個技巧可以將迴圈和條件語句壓縮成單一的表達式。
IF
python
a = "🔥" if weight >= 60 else "😭"這行程式碼使用了條件表達式，根據 weight 的值來賦值給變數 a。如果 weight 大於等於 60，a 將被賦值為 🔥 表情；如果 weight 小於 60，則 a 將被賦值為 😭 表情。這是一種簡潔的寫法，
FOR
python
squares = [x ** 2 for x in range(1, 6)]
# 結果為 [1, 4, 9, 16, 25]範例 1: 創建一個包含平方數的 List
python
even_numbers = [x for x in range(1, 11) if x % 2 == 0]它的結果會是 [2, 4, 6, 8, 10]，這個 List 包含了範圍從 1 到 10 中的所有偶數數字。
範例 2: 將字串中的字母轉換成大寫
python
text = "hello world"
uppercase_letters = [letter.upper() for letter in text if letter.isalpha()]
# 結果為 ['H', 'E', 'L', 'L', 'O', 'W', 'O', 'R', 'L', 'D']if 和 for 的結合
python
a = ["🔥" if weight >= 60 else "😭" for weight in [80, 70, 50, 40]]
# a = ["🔥","🔥","😭","😭"]範例 3: 使用嵌套一行寫法創建九九乘法表
python
[print(f'{i} * {j} = {i*j}', end='\n') if j == 9 else print(f'{i} * {j} = {i*j:<3d}', end=' ') for i in range(10) for j in range(10)]
'''
0 * 0 = 0 0 * 1 = 0 0 * 2 = 0 0 * 3 = 0 0 * 4 = 0 0 * 5 = 0 0 * 6 = 0 0 * 7 = 0 0 * 8 = 0 0 * 9 = 0
1 * 0 = 0 1 * 1 = 1 1 * 2 = 2 1 * 3 = 3 1 * 4 = 4 1 * 5 = 5 1 * 6 = 6 1 * 7 = 7 1 * 8 = 8 1 * 9 = 9
2 * 0 = 0 2 * 1 = 2 2 * 2 = 4 2 * 3 = 6 2 * 4 = 8 2 * 5 = 10 2 * 6 = 12 2 * 7 = 14 2 * 8 = 16 2 * 9 = 18
3 * 0 = 0 3 * 1 = 3 3 * 2 = 6 3 * 3 = 9 3 * 4 = 12 3 * 5 = 15 3 * 6 = 18 3 * 7 = 21 3 * 8 = 24 3 * 9 = 27
4 * 0 = 0 4 * 1 = 4 4 * 2 = 8 4 * 3 = 12 4 * 4 = 16 4 * 5 = 20 4 * 6 = 24 4 * 7 = 28 4 * 8 = 32 4 * 9 = 36
5 * 0 = 0 5 * 1 = 5 5 * 2 = 10 5 * 3 = 15 5 * 4 = 20 5 * 5 = 25 5 * 6 = 30 5 * 7 = 35 5 * 8 = 40 5 * 9 = 45
6 * 0 = 0 6 * 1 = 6 6 * 2 = 12 6 * 3 = 18 6 * 4 = 24 6 * 5 = 30 6 * 6 = 36 6 * 7 = 42 6 * 8 = 48 6 * 9 = 54
7 * 0 = 0 7 * 1 = 7 7 * 2 = 14 7 * 3 = 21 7 * 4 = 28 7 * 5 = 35 7 * 6 = 42 7 * 7 = 49 7 * 8 = 56 7 * 9 = 63
8 * 0 = 0 8 * 1 = 8 8 * 2 = 16 8 * 3 = 24 8 * 4 = 32 8 * 5 = 40 8 * 6 = 48 8 * 7 = 56 8 * 8 = 64 8 * 9 = 72
9 * 0 = 0 9 * 1 = 9 9 * 2 = 18 9 * 3 = 27 9 * 4 = 36 9 * 5 = 45 9 * 6 = 54 9 * 7 = 63 9 * 8 = 72 9 * 9 = 81
'''DICT
使用一行寫法創建字典，將數字作為鍵，其平方作為值
python
square_dict = {x: x ** 2 for x in range(1, 6)}
# 結果為 {1: 1, 2: 4, 3: 9, 4: 16, 5: 25}Contributors
lucashsu95