Lab 12: Find the most frequent words in a text read from a file

Write a Python program to compute the most frequently used words from the text file.

Example

python frequent.py file1.txt -> file1.txt, "the" 12

Pre-Lab Questions

1. Distinguish between syntax errors (compile time) and exceptions (run time).

2. There may not exist a file with the user provided filename(s) on the command line. In that case, a built-in OS-level exception will be raised when the program is executed. Write a Python function open_file(filename) that handles the appropriate exception (https://docs.python.org/3/library/exceptions.html#FileNotFoundError) and re-raise the exception (allowing a caller to handle the exception as well). To help you get started, the basic code for open_file is already provided below.

   def open_file(filename):
       file = open(filename, 'r')
   	return file

3. When such a function open_file()is called with the appropriate argument, it is recommended coding practice to have exception handling code in the calling code or function to handle OS_exceptions. What would that exception handling code be for handling the specific exception which was raised in the previous question?

4. What is the difference between a text file and a binary file?

5. Imagine that the user specifies a filename, and a file exists with the same name but it happens to be a binary file and not a text file. If the program tries to read a binary file when it is expecting a text file, other exceptions will occur. What additional exception handling code would you add to handle all other types of exceptions that may arise, including the binary file scenario?

Post-lab Questions

1. How can you compare whether two files are equal in Python?

   python -c "print open('f0.txt', 'rb').read() == open('f1.txt', 'rb').read()"

Related Material

http://programmingzen.com/use-python-to-detect-the-most-frequent-words-in-a-file/

http://mcsp.wartburg.edu/zelle/python/sigcse-workshop/mgp00047.html