#!/usr/bin/python3
import os
import sys

result = os.popen('find . -name "*.sdf*"')## not  os.system
res    = result.read()
print(res)
res_split = res.splitlines() ## split with '\n'
for line in res_split :
    print("%s\n" % (line))
    line_split = line.split('.')
    if 'half_base' in line:
        continue
    else :
        if line_split[-1] == 'gz' :
            os.system("gzip -d %s" % (line))
            line_no_gz = '.'.join(line_split[0:-1])
        else :
            line_no_gz = line

        os.system(r'sed -i "s/\
              
                /0/g" %s' % (line_no_gz))
        os.system("gzip %s" % (line_no_gz))
              
            
          

以上代碼給出：
1.如何調(diào)用system cmd
2.system cmd有參數(shù)如何處理
3.如何get system的返回值

4.有環(huán)境變量符號(hào)$如何替換