python/mixture/phred.py

   1 #!/usr/bin/env python
   2
   3 class PhredHelper:
   4     def __init__(self, offset=33):
   5         if offset != 33 and offset != 64:
   6             sys.err.write("PhredHelper: invalid offset specified. Using default (Sanger 'Q+33')")
   7             self.offset = 33
   8         else:
   9             self.offset = offset
  10
  11     def char_to_int(self, char):
  12         raw_val = ord(char)
  13         phred_val = raw_val - self.offset
  14         return phred_val
  15
  16     def int_to_char(self, num):
  17         return chr(num + self.offset)