Python for Absolute Beginners Transcripts
Chapter: Course conclusion
Lecture: Review: File I/O
0:00 Once we rewrote our Rock Paper Scissor game
0:03 with data structures
0:04 it turns out it's pretty easy
0:06 to save and load those data structures from files.
0:09 The next topic we covered was File IO
0:12 and File IO usually starts around the open function.
0:15 The open function creates this file string
0:18 either an input or output string
0:20 and you need to make sure
0:21 it gets flushed and closed properly
0:23 so you want to put it into a width block.
0:25 That's what we're doing at the bottom
0:26 of this screen here.
0:27 With open, give it a file, this one's for reading
0:30 so we say R, specify the encoding just to be explicit there
0:33 and we give it a variable name, Fin.
0:36 I like fin for file input string
0:38 so the name tells you, you can't write to it
0:40 and here we're actually going to load up a JSON file
0:43 so we don't need to understand how JSON works.
0:45 All we need to do is input the JSON library
0:47 and say, hey, here's a file string
0:48 to something you understand.
0:50 Go get us the data, put it into rows.
0:52 That will be a dictionary on the Python side of things.
0:55 We also saw that working with paths is tricky
0:58 and knowing where you're actually located
1:00 can be a challenge.
1:01 Remember, this is based on the working directory.
1:04 And trying to put these together and work with them
1:06 is also tricky in a cross-platform way.
1:08 Windows and POSIX macOS, Linux systems
1:12 have different separators and definitions
1:14 of how you put files together.
1:16 That's why we use the OS.path module
1:19 because it knows how to do this for us
1:21 regardless of the operating system we're on.
1:23 This is just one of the things
1:24 we did with files throughout the course
1:26 and I think you'll agree
1:27 they added a lot to our little program.