grep命令，查找某个变量在哪儿地方赋值

-bash-4.2$ cat ~/test/zMail_grep_test/0406-1900/grep.py
#!/usr/bin/python3
# -*- coding:UTF-8 -*-
import sys
import os
import glob
import re
import subprocess


if len(sys.argv) < 3:
        print("Usage: ./xx.py grep_str 1/0(1==member[eg: ., ->], 0==gobal) dir(optional))")
        sys.exit()

for i in range(1, len(sys.argv)):
        pass
        #print("para",i,":", sys.argv[i])

grep_str=sys.argv[1]
member=sys.argv[2]

if (len(sys.argv) == 4):
        dir=" " + sys.argv[3]
else:
        dir=" ./"

#grep -rn '\.sum_exec_runtime +=' ./ member_str="\."
#grep -rn '\.sum_exec_runtime +=' ./ assign_str="+="
member_str=["'", "'"]
if (int(member,10) == int('1', 10)):
        member_str=["'\.", "'\->"]

assign_str=[" ='", " +='", " -='", "++'", "--'"]

for i in range(0, len(member_str)):
        for j in range(0, len(assign_str)):
                cmd_str="grep -rn " + member_str[i] + grep_str + assign_str[j] + dir
                #print(cmd_str)
                os.system(cmd_str)