diff --git a/httprunner/parser.py b/httprunner/parser.py
index 4a85ac65..a2147a52 100644
--- a/httprunner/parser.py
+++ b/httprunner/parser.py
@@ -2,11 +2,10 @@
 
 import ast
 import builtins
-import os
 import re
 
 from httprunner import exceptions, utils, validator
-from httprunner.compat import basestring, builtin_str, numeric_types, str
+from httprunner.compat import basestring, numeric_types, str
 
 # use $$ to escape $ notation
 dolloar_regex_compile = re.compile(r"\$\$")
diff --git a/httprunner/response.py b/httprunner/response.py
index aef4e9a1..6520794a 100644
--- a/httprunner/response.py
+++ b/httprunner/response.py
@@ -5,8 +5,6 @@ import re
 
 from httprunner import exceptions, logger, utils
 from httprunner.compat import OrderedDict, basestring, is_py2
-from requests.models import PreparedRequest
-from requests.structures import CaseInsensitiveDict
 
 text_extractor_regexp_compile = re.compile(r".*\(.*\).*")
 
@@ -81,7 +79,7 @@ class ResponseObject(object):
                 "content.person.name.first_name"
 
         """
-        # string.split(sep=None, maxsplit=-1) -> list of strings
+        # string.split(sep=None, maxsplit=1) -> list of strings
         # e.g. "content.person.name" => ["content", "person.name"]
         try:
             top_query, sub_query = field.split('.', 1)