Basic python tutorial-HelloWorld!

This article mainly introduces the basic python tutorial HelloWorld !, This article describes the example of HelloWorld output in the command line, in the file, and in the script file. For more information, see Python command line

If you have installed Python, enter the following command in the Linux Command Line:

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$ Python

Directly go to python. Then, at the command line prompt >>>, enter:

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>>> Print ('Hello World! ')

You can see that, and then output on the screen:

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Hello World!

Print is a common function, which is a string in the output brackets.

(In Python 2.x, print can also be a keyword and can be written as print 'Hello World! ', But this does not work in 3.x)

Write a small program

Another way to use Python is to write a Python program. Use a text editor to write a file ending with. py, such as hello. py.

Write and save the following in hello. py:

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Print ('Hello World! ')

Exit the text editor and enter:

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$ Python hello. py

To run hello. py. You can see the subsequent output of Python.

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Hello World!

Script

We can also change the Python program hello. py to an executable script and execute it directly:

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#! /Usr/bin/env python
Print ('Hello World! ')

You need to modify the permissions of the above program to execute:

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Chmod 755 hello. py

Then, enter

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./Hello. py

You can run it directly.

Summary

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Print

Command Line Mode: Run Python and enter the command in the command line and execute it.

Program mode: Write and run a Python program.