String Compression

string_compression_1_6.py

#!/usr/bin/env python

# String Compression
# Implement a method to perform basic string compression using the counts of repeated characters.
# For example, the string aabcccccaaa would become a2b1c5a3. If the "compressed" string would not
# become smaller than the original string, your method should return the original string.
# You can assume the string has only uppercase and lowercase letters(a-z)

import sys

SAMPLE_INPUT = "aabcccccaaa"

class StringCompression:
  def __init__(self, org_str):
    self.org_str = org_str

  def run_compression(self):
    org_str_len = len(self.org_str)
    result = ""

    current_char = self.org_str[0]
    count_char = 1
    for i, c in enumerate(self.org_str):
      c = c.lower()

      if c != current_char or i == (org_str_len - 1):
        result += ("%s%d" % (current_char, count_char))
        current_char = c
        count_char = 1
      elif c == current_char:
        count_char += 1

    if len(result) > org_str_len:
      result = self.org_str

    return result

  def run_compression_v2(self):
    pass
    # We can optimize the logic with bit operation

if __name__ == '__main__':
  input_value = sys.argv[1] if len(sys.argv) > 1 else SAMPLE_INPUT

  string_compression = StringCompression(input_value)
  result_value = string_compression.run_compression()

  print "%s is compressed to %s" % (input_value, result_value)