import re
regex = r"\{'[^']+':\s*\['([^][]+)'\]}"
test_str = ("email id\n"
"{'email': ['test@test.com']} {'id': ['123abc_d456_789_fgh']}")
subst = "\\1"
result = re.sub(regex, subst, test_str, 0)
if result:
print (result)
aW1wb3J0IHJlCgpyZWdleCA9IHIiXHsnW14nXSsnOlxzKlxbJyhbXl1bXSspJ1xdfSIKCnRlc3Rfc3RyID0gKCJlbWFpbCAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgIGlkXG4iCgkieydlbWFpbCc6IFsndGVzdEB0ZXN0LmNvbSddfSAgICAgICAgICAgeydpZCc6IFsnMTIzYWJjX2Q0NTZfNzg5X2ZnaCddfSIpCgpzdWJzdCA9ICJcXDEiCgpyZXN1bHQgPSByZS5zdWIocmVnZXgsIHN1YnN0LCB0ZXN0X3N0ciwgMCkKCmlmIHJlc3VsdDoKICAgIHByaW50IChyZXN1bHQpCgo=