怎样在python中写多行语句

一般来说, 一行就是一条语句, 但有时语句过长不利于阅读, 一般会写成多行的形式, 这时需要在换行时使用反斜杠:

name = "Lilei"
age = 23
gender = "boy"

str = "Hello, my name is " + 
    name + 
    ". I'm " + 
    str(age) + 
    "years old " + 
    gender

print(str)

# Hello, my name is Lilei. I'm 23years old boy

如果语句换行时包裹在中括号: [], 大括号: {}, 或者括号: (), 中, 则不必反斜杠换行, 如下: 

name = "Lilei"
age = 23
gender = "boy"

str = ("Hello, my name is " + 
    name + 
    ". I'm " + 
    str(age) + 
    "years old " + 
    gender)

print(str)