Python executes "Hello World" program-003

How Python is executed

1. Execute with python command

(1) Create a file hello.py file under Linux and enter

Print ("Hello world!")

(2) then execute the command: Python hello.py, output result

[Email protected] ~]# vim hello.py

[email protected] ~]# cat hello.py

Print ("Hello world!")

[email protected] ~]# python hello.py

Hello world!

[Email protected] ~]#

2. Specify interpreter execution

(1) When we execute hello.py in the first step, we explicitly point out that the Python interpreter executes the

(2) If we want to execute a python script like executing a shell script, we need to specify the interpreter in the script:./hello.py

[Email protected] ~]# vim hello.py

[email protected] ~]# cat hello.py

#!/usr/bin/env Pythn

Print ("Hello world!")

[Email protected] ~]# chmod +x hello.py #赋予脚本执行权限

[Email protected] ~]# vim hello.py

[Email protected] ~]#./hello.py

Hello world!

[Email protected] ~]#

3. Execute in the interactive device

(1) We can directly invoke Python's own interactive runtime code

[[email protected] ~]# python

Python 2.6.6 (r266:84292, 18 2016, 15:13:37)

[GCC 4.4.7 20120313 (Red Hat 4.4.7-17)] on linux2

Type "Help", "copyright", "credits" or "license" for more information.

>>> print ("Hello world!")

Hello world!

>>> exit ()

[Email protected] ~]#

Python executes "Hello World" program-003