python编码一定会用到的七个小技巧，不看你一定会后悔哦~

# -*- coding:utf-8 -*-
#author:菜鸟小白的学习分享
#交换变量
a=1
b=2
temp=0
print(a,b)

temp=a
a=b
b=temp
print(a,b)

# -*- coding:utf-8 -*-
#author:菜鸟小白的学习分享
#交换变量
a=1
b=2
print(a,b)

a,b=b,a
print(a,b)

# -*- coding:utf-8 -*-
#author:菜鸟小白的学习分享
#取出列表的子集
words = ['菜鸟', '小白的', '学习', '分享']
sub = words[:2]
print(sub)

# -*- coding:utf-8 -*-
#author:菜鸟小白的学习分享
#取出字符串的子串
words = '菜鸟小白的学习分享'
sub = words[:4]
print(sub)

# -*- coding:utf-8 -*-
#author:菜鸟小白的学习分享
flag = True
if flag:
    x = 1
else:
    x = 2
print(x)

# -*- coding:utf-8 -*-
#author:菜鸟小白的学习分享
flag = True
x = 1 if flag else 2
print(x)

# -*- coding:utf-8 -*-
#author:菜鸟小白的学习分享
#文件打开关闭
f = open('菜鸟小白.txt','r',encoding='utf-8')
contents = f.read()
f.close()

words = contents.split(' ')
word_counts =  len(words)
print(word_counts)

# -*- coding:utf-8 -*-
#author:菜鸟小白的学习分享
#文件打开关闭
with open('菜鸟小白.txt','r',encoding='utf-8') as f:
    contents = f.read()
    words = contents.split(' ')
    word_counts =  len(words)
    print(word_counts)

# -*- coding:utf-8 -*-
#author:菜鸟小白的学习分享
#下标的使用
words=['菜鸟','小白','学习','分享']
index=0
for name in words:
    print (index,words)
    index+=1

# -*- coding:utf-8 -*-
#author:菜鸟小白的学习分享
#下标的使用
words=['菜鸟','小白','学习','分享']
for index,name in enumerate(words):
    print (index,words)

# -*- coding:utf-8 -*-
#author:菜鸟小白的学习分享
#遍历多个序列
words=['菜鸟','小白的','学习','分享']
nums=[2,3,2,2]
for index,word in enumerate(words):
    num=nums[index]
    print (f'{word} 有 {num} 个字')

# -*- coding:utf-8 -*-
#author:菜鸟小白的学习分享
#遍历多个序列
words=['菜鸟','小白的','学习','分享']
nums=[2,3,2,2]
for word,num in zip(words,nums):
    print (f'{word} 有 {num} 个字')

# -*- coding:utf-8 -*-
#author:菜鸟小白的学习分享
#dir
words=['菜鸟','小白的','学习','分享']
print(dir(words))

"C:\Program Files\Python36\python.exe" C:/Users/admin/PycharmProjects/20200701/test.py
['__add__', '__class__', '__contains__', '__delattr__', '__delitem__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__init_subclass__', '__iter__', '__le__', '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__reversed__', '__rmul__', '__setattr__', '__setitem__', '__sizeof__', '__str__', '__subclasshook__', 'append', 'clear', 'copy', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort']

Process finished with exit code 0