Difference read, readline, readlines of

This article speaks to read the file in Python and uses the difference between the read (), readline () and readlines () method of the three.
read: read the entire file. 
readline: read the next line, the method using generators. 
readlines: read the entire file into an iterator for us to traverse.
Here's a look at the implementation code.
Test1.txt to prepare a document, which reads as follows:
<ignore_js_op>  
Read () method reads the file from the current position until the end of the file, as a String object that range:
<ignore_js_op>  
result output is:
<ignore_js_op>  
the readline () method of each line is read content, therefore, read the small memory footprint, more suitable for large files, the method returns a string object:
<ignore_js_op>  
output:
<ignore_js_op>  


the readlines () to read the entire file all lines stored in a list (list) variable per line as an element, but read large files would be more total memory:
<ignore_js_op>  
output is:
<ignore_js_op> 
more technical information may concern: gzitcast