- 系统关键字不能用于标识符的命名
# 流程控制:if else elif while for continue break
# 系统常量:True False None
# 变量函数类:global def lambda class return yield pass
# 逻辑运算符:and or not in is
# 导入:from import
# 异常:try except finally raise
# 文件:with as
# 其它:del assert nonlocal ...
# 流程控制:if else elif while for continue break
# 系统常量:True False None
# 变量函数类:global def lambda class return yield pass
# 逻辑运算符:and or not in is
# 导入:from import
# 异常:try except finally raise
# 文件:with as
# 其它:del assert nonlocal ...