Python语法简洁，能够用一行代码实现很多有趣的功能，这次来整理30个常见的Python一行代码集合。
1、转置矩阵
- old_list = [[1, 2, 3], [3, 4, 6], [5, 6, 7]]
- list(list(x) for x in zip(*old_list))
[[1, 3, 5], [2, 4, 6], [3, 6, 7]]
2、二进制转十进制
- decimal = int('1010', 2)
- print(decimal) #10
10
3、字符串大写转小写
- # 方法一 lower()
- "Hi my name is Allwin".lower()
- # 'hi my name is allwin'
- # 方法二 casefold()
- "Hi my name is Allwin".casefold()
- # 'hi my name is allwin'
'hi my name is allwin'
4、字符串小写转大写
- "hi my name is Allwin".upper()
- # 'HI MY NAME IS ALLWIN'
'HI MY NAME IS ALLWIN'
5、将字符串转换为字节
- "convert string to bytes using encode method".encode()
- # b'convert string to bytes using encode method'
b'convert string to bytes using encode method'
6、复制文件内容
- import shutil; shutil.copyfile('source.txt', 'dest.txt')
'dest.txt'
7、快速排序
- 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]])
- qsort([1,3,2])
[1, 2, 3]
8、n个连续数之和
- n = 3
- sum(range(0, n+1))
6
9、交换两个变量
- a=1
- b=2
a,b = b,a
10、斐波那契数列
- fib = lambda x: x if x<=1 else fib(x-1) + fib(x-2)
- fib(10)
55
11、将嵌套列表合并为一个列表
- main_list = [[1,2],[3,4],[5,6,7]]
- [item for sublist in main_list for item in sublist]
[1, 2, 3, 4, 5, 6, 7]
12、运行 HTTP 服务器
- python3 -m http.server 8000
13、反转列表
- numbers = 'I Love China'
- numbers[::-1]
'anihC evoL I'
14、返回阶乘
- import math; fact_5 = math.factorial(5)
- fact_5
120
15、判断列表推导式
- even_list = [number for number in [1, 2, 3, 4] if number % 2 == 0]
- even_list
[2, 4]
16、取最长字符串
- words = ['This', 'is', 'a', 'list', 'of', 'words']
- max(words, key=len)
'words'
17、列表推导式
- li = [num for num in range(0,100)]
- # this will create a list of numbers from 0 to 99
18、集合推导式
- num_set = { num for num in range(0,100)}
- # this will create a set of numbers from 0 to 99
19、字典推导式
- dict_numbers = {x:x*x for x in range(1,5) }
- # {1: 1, 2: 4, 3: 9, 4: 16}
20、if-else
- print("even") if 4%2==0 else print("odd")
even
21、无限循环
- while 1:0
22、检查数据类型
- isinstance(2, int)
- isinstance("allwin", str)
- isinstance([3,4,1997], list)
23、while循环
- a=5
- while a > 0: a = a - 1; print(a)
24、使用print语句写入到文件里
- print("Hello, World!", file=open('source.txt', 'w'))
25、统计字频
- print("umbrella".count('l'))
2
26、合并两个列表
- list1.extend(list2)
- # contents of list 2 will be added to the list1
27、合并两个字典
- dict1.update(dict2)
- # contents of dictionary 2 will be added to the dictionary 1
28、合并两个集合
- set1.update(set2)
- # contents of set2 will be copied to the set1
29、时间戳
- import time; print(time.time())
1632146103.8406303
30、统计最多的元素
- test_list = [9, 4, 5, 4, 4, 5, 9, 5, 4]
- most_frequent_element = max(set(test_list), key=test_list.count)
- most_frequent_element
最后，Python代码哲学崇尚简洁，伙伴们也可以尝试把代码简化，看能不能实现想要的功能。
