iTunes：应用版本2.1和上传版本3.0（1.0）(iTunes: app version 2.1 and uploaded build version 3.0 (1.0))

 使用翻译表： 
 
import string
table = string.maketrans('ACGT', 'TGCA')
 
 您可以像这样应用转换： 
 
with open(from_file) as f:
    contents = f.read()

contents = contents.translate(table)  # Swap A<->T and C<->G
contents = contents[::-1]  # Reverse the string

with open(to_file, 'w') as f:
    f.write(contents)

Use a translation table:
 
import string
table = string.maketrans('ACGT', 'TGCA')
 
You can apply the transformation like this:
 
with open(from_file) as f:
    contents = f.read()

contents = contents.translate(table)  # Swap A<->T and C<->G
contents = contents[::-1]  # Reverse the string

with open(to_file, 'w') as f:
    f.write(contents)