python - Key error in dna complement -
python - Key error in dna complement -       import string import os,sys  file=open("c:\python27\\new text document.txt",'r')\ seq =file.readlines() basecomplement = {'a': 't', 'c': 'g', 'g': 'c', 't': 'a'}  def translate(seq):     aaseq = []     str in seq:        aaseq.append(basecomplement[str])      homecoming aaseq  frame in range(1):     rseqn= (''.join(item.split('|')[0] item in translate(seq[frame:])))  rseqn = rseqn[::-1]     print(rseqn) print(seq)     error here   file    "c:\users\ram\desktop\pythonhw\dnacomp.py", line 13, in <module> rseqn= (''.join(item.split('|')[0] item in translate(seq[frame:])))   file  "c:\users\ram\desktop\pythonhw\dnacomp.py", line 10, in translate aaseq.append(basecomplement[str]) keyerror: 'agtctggcataccagtacagactatca'    if  utilize simple string getting sequence tried read file input shows  next err...