Welcome to the Treehouse Community
Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.
Looking to learn something new?
Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.
Start your free trial
Brendan Whiting
Front End Web Development Techdegree Graduate 84,736 PointsWhat's the difference between sys.stdin.read() and input()?
We have both in this video and I'm not sure what the difference is.
2 Answers
Evan Demaris
64,262 PointsHi Brendan, in this video the "sys.stdin.read()" is described as being able to take a newline and finish your entry with Control+D. input() would finish your entry with the "Enter" key being pressed on your keyboard, so you couldn't include a newline in your data input that way.
Evan Demaris
64,262 PointsThat sounds roughly correct, however input() also takes as an argument a string to use as a prompt, while sys.stdin.read() takes the length to read into the user-entered string as an optional argument instead (and provides no prompt - in the video, a print() was provided to serve as a prompt instead). For more information on what these functions are doing though, you can use help(sys.stdin.read) and help(input) while in a Python interpreter, or visit https://docs.python.org/2/library/sys.html for more information about the sys library and its methods, including stdin.
As for your other question, we have to import the sys library because sys.stdin.read() is reflecting a method that exists only in that library. The reason it's so long is that we just imported the library, so we have to reference sys at the beginning of any function from that library, then .stdin() is a function with a .read() method available in it (among others) - so it wouldn't make sense to just say read() without telling Python which read() method you're asking it to use (other functions, including one you write yourself, could include their own read() methods).
If you mean to say why sys is a library instead of being ready for use in Python all the time, that's likely because it would be inefficient for Python to keep libraries loaded if they aren't being used, so the library is kept optional.
Brendan Whiting
Front End Web Development Techdegree Graduate 84,736 PointsCool that makes sense thanks.
Chris Freeman
Treehouse Moderator 68,423 PointsChris Freeman
Treehouse Moderator 68,423 PointsChanged comment to answer
Brendan Whiting
Front End Web Development Techdegree Graduate 84,736 PointsBrendan Whiting
Front End Web Development Techdegree Graduate 84,736 PointsSorry - just to just to make sure I'm following - sys.stdin.read can take multiple lines and ends when the user presses Ctrl+D, input takes only one line and ends when the user presses Enter. Other than that they're the same? Why do they have such different names? Why do we have to import the sys library in order to use one but not the other since they both involve the console?
Thx.