hazelement / word_counter_exercise

Programming Exercise

Description

Question

Given a comma seperated list of words in a single file, return the number of times the word was seen.

The input will be in the form of a text file.

Example input

green,green,red,green,red

Expected output

green,3
red,2

Input Assumptions

1. leading and trailing "," is ignored, ",," is ignored
2. word length is not checked. max word length is python array size limit. 536870912 on a 32 bit system
3. all characters are assumed ascii characters

Requirement

python3.6 and above

To check python version:

$ python --version
Python 3.7.1

Usage

From project root directory,

$ python count_word.py input_file word1 word2 ...

Example:

$ python count_word.py tests/data/case1.in ab bc
ab,2
bc,2

$ python count_word.py tests/data/case1.in ab bc f
ab,2
bc,2
f,0

Tests

To run test, issue folowing command from project directory

$ python -m unittest discover tests
......
----------------------------------------------------------------------
Ran 6 tests in 0.007s

OK

To add more test cases, refer to existing test files in tests/data.

Each test case consists of 2 files, *.in and *.cmp. The two file names must match.

1. *.in is input file with only one line in the file, for example green,green,red,red.
2. *.cmp is the truth file for comparison, each line is a word and its occurance seperated by comma.