▍1、交换两个变量

# a = 4 b = 5
a,b = b,a
# print(a,b) >> 5,4

2、多个变量赋值 

a,b,c = 4,5.5,'Hello'
#print(a,b,c) >> 4,5.5,hello

a,b,*c = [1,2,3,4,5]
print(a,b,c)
> 1 2 [3,4,5]

▍3、列表中偶数的和

a = [1,2,3,4,5,6]
s = sum([num for num in a if num%2 == 0])
print(s)
>> 12

▍4、从列表中删除多个元素

# Deleting all even
a = [1,2,3,4,5]
del a[1::2]
print(a)

>[1, 3, 5]

a

▍5、读取文件

lst = [line.strip() for line in open('data.txt')]
print(lst)

list(open('data.txt'))

##Using with will also close the file after use
with open("data.txt") as f:
    lst=[line.strip() for line in f]
print(lst)

▍6、将数据写入文件

with open("data.txt",'a',newline='\n') as f: 
    f.write("Python is awsome")

▍7、创建列表

lst = [i for i in range(0,10)]
print(lst)
> [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

or

lst = list(range(0,10))
print(lst)

　　

lst = [("Hello "+i) for i in ['Karl','Abhay','Zen']]
print(lst)
> ['Hello Karl', 'Hello Abhay', 'Hello Zen']

　▍8、映射列表或类型转换整个列表

list(map(int,['1','2','3']))
> [1, 2, 3]

list(map(float,[1,2,3]))
> [1.0, 2.0, 3.0]

[float(i) for i in [1,2,3]]
> [1.0, 2.0, 3.0]

　▍9、创建集合

# Square of all even numbers in an range
{x**2 for x in range(10) if x%2==0}

> {0, 4, 16, 36, 64}

　▍10、Fizz Buzz

['FizzBuzz' if i%3==0 and i%5==0
    else 'Fizz' if i%3==0 
    else 'Buzz' if i%5==0 
    else i  for i in range(1,20)]

　▍11、回文

text = 'level'
ispalindrome = text == text[::-1]
ispalindrome

> True

▍12、用空格分隔的整数到一个列表

lis = list(map(int, input().split()))
print

▍13、Lambda函数 

# Function that returns square of any number
sqr = lambda x: x * x
sqr(10)

> 100

▍14、检查列表中数字的存在

num = 5
if num in [1,2,3,4,5]:
     print('present')

> present  

▍15、打印图案

n = 5

print('\n'.join('