Simple compression and decompression algorithms for strings written in python.

• The input is a string, and the output is a compressed string.
• A valid input consists of zero or more upper case english letters A-Z.
• To produce the compressed output, any run of two or more of the same character should be converted to two of that character plus a number indicating how many repeated runs were compressed.
• Examples:
  • A --> A
  • AA --> AA0
  • AAA --> AA1
  • AAAA --> AA2
• Only one digit may be used at a time, so if the run is quite long, then you must use multiple character/number pairs
  • AAAAAAAAAA --> AA8
  • AAAAAAAAAAA --> AA9
  • AAAAAAAAAAAA --> AA9A
  • AAAAAAAAAAAAA --> AA9AA0
  • AAAAAAAAAAAAAA --> AA9AA1

The decompression algorithm simply reverses this process.

The algorithms 'compress' and 'decompress' are located in compression.py.

• The bash script compression.sh runs them easily from the command line.
• The first argument should be 'compress' or 'decompress' to specify the algorithm.
• The script runs the main function which reads strings from standard input until EOF or CTRL+C.
• Example usage:
  • $ ./compress.sh compress
  • HELLOOOOO
  • HELL0OO3
  • ^C
  • $ ./compress.sh decompress
  • HELL0OO3
  • HELLOOOOO
  • ^C
• This input format allows the input of files with output to another file:
  • $ ./compress compress < toCompress.txt > output.txt

Unit tests are located in tests.py

• To run Tests:
  • $ python tests.py