1 def write_file(filename,content):#filename，content都是形式参数
2 with open(filename,'a+',encoding='utf-8') as fw:
3 fw.write(content+'\n')
4
5
6 def read_file(filename):
7 with open(filename,encoding='utf-8') as fr:
8 result = fr.read()
9 return result#返回值，什么时候需要返回值，要看具体函数的作用
10 #函数里面遇到return,函数立即结束
11
12 write_file('a.txt','aaaaaa')
13 rea = read_file('a.txt')#a.txt是实际参数
14 print(rea)
15
16 def more():
17 name = 'xiaoming'
18 age = 18
19 score = 99
20 return name,age,score
21 #多个返回值
22 # 方法1
23 result = more()
24 print(result)
25 # 方法2
26 name,age,score = more()# 用3个值来接收
27 print(name)
28 print(age)
29 print(score)
30
31 # 默认值参数
32 def user(name,sex='女'):
33 print(name,sex)
34 user('xiaobai','男')
35 user('xiaolan')
