#!/opt/chipster/tools/Python-2.7.12/bin/python """ For every column that occurs in a multiple alignment print the column and the number of times it occurs (one column/count per line, tab separated), sorted by count descending. Note: all blocks must have exactly the same number of species. usage: %prog < maf > column_counts """ from __future__ import print_function import sys from itertools import * import bx.align.maf counts = {} nspecies = None for block in bx.align.maf.Reader( sys.stdin ): # Ensure all blocks have the same number of rows if nspecies: assert len( block.components ) == nspecies else: nspecies = len( block.components ) # Increment count for each column for col in zip( * [ iter( comp.text.upper() ) for comp in block.components ] ): try: counts[ col ] += 1 except: counts[ col ] = 1 counts = [ ( value, key ) for key, value in counts.items() ] counts.sort() counts.reverse() # print len( counts ) for count, col in counts: print("".join(col), count)