Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
328 views
in Technique[技术] by (71.8m points)

grammar - How does the right-shift operator work in a python print statement?

I've seen someone using "print" with ">>" to write stuffs into a file:

In [7]: with open('text', 'w') as f:
   ...:     print >> f, "Hello, world!"
   ...:

In [8]: !type text
Hello, world!

How does it work? When should I use this instead of just using the "write" method?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

From https://docs.python.org/2/reference/simple_stmts.html#the-print-statement

print also has an extended form, defined by the second portion of the syntax described above. This form is sometimes referred to as “print chevron.” In this form, the first expression after the >> must evaluate to a “file-like” object, specifically an object that has a write() method as described above. With this extended form, the subsequent expressions are printed to this file object. If the first expression evaluates to None, then sys.stdout is used as the file for output.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...