class_notes.md

Class notes from 2018-10-02

Step 1: Figure out what does wc actually do?

• use $ man wc at the command line to read the manual for wc
• it returns the number of lines, words, and bytes (characters) of a file

example:

$ wc test_files/constitution.txt
     872    7652   45119 test_files/constitution.txt

Step 2: Write out a description of what your program needs to do

First, as with just about any program you write, it's useful thinking about what the INPUT(s) and OUTPUT(s) should be.

In this case, - INPUT: a file path - OUTPUTs: - count of lines - count of words - count of bytes

Note: the wc utility actually allows you to provide many files as inputs and returns counts for each of them. In this assignment, we won't worry about that though.

Next, we should write out what our code will do in plain language. In other words, given our INPUTs, how do we get to our OUTPUTs. In class, here's what we came up with:

1. Get our input file as a commandline argument (probably using argparse)
2. Open the file
3. Initialize variables for lines, words, and bytes
4. Read the file line by line
   1. for each line, add 1 to the lines variable
   2. to count the number of words, use .split() on the line, then use len() on the list that's returned
      1. don't forget to add that number to the words variable!
   3. to count the number of bytes, use len() on the line string itself
      1. don't forget to add that number to the bytes variable!
5. Once we've read through the file, print the values of lines, words, and bytes to the screen
6. Close the file

Step 3: Start translating your plan into python syntax