Day 1
写一个 CLI 工具，输入姓名打印问候语
v1 cat echo.py
name = 'evan'
print( name + " have a good day")
v2
➜ py2025 cat echo.py
name = input("please input your name")
print( name + " have a good day")
py echo.py
please input your name evan
evan have a good day
➜ py2025 cat echo.py
v3
