How does python read data from a file?

The recent self-learning python progress is relatively slow, the work of intermittent look at the efficiency is lower, it seems to be ruthless to make a little progress every day.

Remember the previous time chef Chen Cat raised a "first to read the local file with Python," happened to see the file and the exception today, combined with the practice of using Python to read the local file code:

Import OS
#从标准库导入os模块

Os.chdir (' F:\HeadFirstPython\chapter3 ')
#切换到包含数据文件的文件夹

data = open (' Sketch.txt ')
#打开一个命名文件, assign the file to a file object named data

For Each_line in data:
    Print (Each_line, end= ")
#循环读取文件没有内容

How does python read data from a file?