We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Python 3 compatibility fix
https://github.com/web2py/web2py/blob/master/gluon/contrib/webclient.py#L124 should be `data['_formname'] = list(self.forms.keys())[0]` to avoid `TypeError: 'dict_keys' object does not support indexing` when this is executing under Python 3.

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `gluon/contrib/webclient.py`
Content:
```
1 """
2 Developed by Massimo Di Pierro
3 Released under the web2py license (LGPL)
4 
5 It an interface on top of urllib2 which simplifies scripting of http requests
6 mostly for testing purposes
7 
8 - customizable
9 - supports basic auth
10 - supports cookies
11 - supports session cookies (tested with web2py sessions)
12 - detects broken session
13 - detects web2py form postbacks and handles formname and formkey
14 - detects web2py tickets
15 
16 Some examples at the bottom.
17 """
18 from __future__ import print_function
19 from gluon._compat import urllib2, cookielib, iteritems, to_native, urlencode, to_bytes
20 import re
21 import time
22 
23 
24 DEFAULT_HEADERS = {
25     'user-agent': 'Mozilla/4.0',  # some servers are picky
26     'accept-language': 'en',
27 }
28 
29 FORM_REGEX = re.compile('(\<input name\="_formkey" type\="hidden" value\="(?P<formkey>.+?)" \/\>)?\<input name\="_formname" type\="hidden" value\="(?P<formname>.+?)" \/\>')
30 
31 SESSION_REGEX = 'session_id_(?P<name>.+)'
32 
33 
34 class WebClient(object):
35 
36     def __init__(self,
37                  app='',
38                  postbacks=True,
39                  default_headers=DEFAULT_HEADERS,
40                  session_regex=SESSION_REGEX):
41         self.app = app
42         self.postbacks = postbacks
43         self.forms = {}
44         self.history = []
45         self.cookies = {}
46         self.cookiejar = cookielib.CookieJar()
47         self.default_headers = default_headers
48         self.sessions = {}
49         self.session_regex = session_regex and re.compile(session_regex)
50         self.headers = {}
51 
52     def _parse_headers_in_cookies(self):
53         self.cookies = {}
54         if 'set-cookie' in self.headers:
55             for item in self.headers['set-cookie'].split(','):
56                 cookie = item[:item.find(';')]
57                 pos = cookie.find('=')
58                 key = cookie[:pos]
59                 value = cookie[pos+1:]
60                 self.cookies[key.strip()] = value.strip()
61 
62     def get(self, url, cookies=None, headers=None, auth=None):
63         return self.post(url, data=None, cookies=cookies,
64                          headers=headers, method='GET')
65 
66     def post(self, url, data=None, cookies=None,
67              headers=None, auth=None, method='auto'):
68         self.url = self.app + url
69 
70         # if this POST form requires a postback do it
71         if data and '_formname' in data and self.postbacks and \
72                 self.history and self.history[-1][1] != self.url:
73             # to bypass the web2py CSRF need to get formkey
74             # before submitting the form
75             self.get(url, cookies=cookies, headers=headers, auth=auth)
76 
77         # unless cookies are specified, recycle cookies
78         if cookies is None:
79             cookies = self.cookies
80         cookies = cookies or {}
81         headers = headers or {}
82 
83         args = [
84             urllib2.HTTPCookieProcessor(self.cookiejar),
85             urllib2.HTTPHandler(debuglevel=0)
86             ]
87         # if required do basic auth
88         if auth:
89             auth_handler = urllib2.HTTPBasicAuthHandler()
90             auth_handler.add_password(**auth)
91             args.append(auth_handler)
92 
93         opener = urllib2.build_opener(*args)
94 
95         # copy headers from dict to list of key,value
96         headers_list = []
97         for key, value in iteritems(self.default_headers):
98             if not key in headers:
99                 headers[key] = value
100         for key, value in iteritems(headers):
101             if isinstance(value, (list, tuple)):
102                 for v in value:
103                     headers_list.append((key, v))
104             else:
105                 headers_list.append((key, value))
106 
107         # move cookies to headers
108         for key, value in iteritems(cookies):
109             headers_list.append(('Cookie', '%s=%s' % (key, value)))
110 
111         # add headers to request
112         for key, value in headers_list:
113             opener.addheaders.append((key, str(value)))
114 
115         # assume everything is ok and make http request
116         error = None
117         try:
118             if isinstance(data, str):
119                 self.method = 'POST' if method=='auto' else method
120             elif isinstance(data, dict):
121                 self.method = 'POST' if method=='auto' else method
122                 # if there is only one form, set _formname automatically
123                 if not '_formname' in data and len(self.forms) == 1:
124                     data['_formname'] = self.forms.keys()[0]
125 
126                 # if there is no formkey but it is known, set it
127                 if '_formname' in data and not '_formkey' in data and \
128                         data['_formname'] in self.forms:
129                     data['_formkey'] = self.forms[data['_formname']]
130 
131                 # time the POST request
132                 data = urlencode(data, doseq=True)
133             else:
134                 self.method = 'GET' if method=='auto' else method
135                 data = None
136             t0 = time.time()
137             self.response = opener.open(self.url, to_bytes(data))
138             self.time = time.time() - t0
139         except urllib2.HTTPError as er:
140             error = er
141             # catch HTTP errors
142             self.time = time.time() - t0
143             self.response = er
144 
145         if hasattr(self.response, 'getcode'):
146             self.status = self.response.getcode()
147         else:#python2.5
148             self.status = None
149 
150         self.text = to_native(self.response.read())
151         # In PY3 self.response.headers are case sensitive
152         self.headers = dict()
153         for h in self.response.headers:
154             self.headers[h.lower()] = self.response.headers[h]
155 
156         # treat web2py tickets as special types of errors
157         if error is not None:
158             if 'web2py_error' in self.headers:
159                 raise RuntimeError(self.headers['web2py_error'])
160             else:
161                 raise error
162 
163         self._parse_headers_in_cookies()
164 
165         # check is a new session id has been issued, symptom of broken session
166         if self.session_regex is not None:
167             for cookie, value in iteritems(self.cookies):
168                 match = self.session_regex.match(cookie)
169                 if match:
170                     name = match.group('name')
171                     if name in self.sessions and self.sessions[name] != value:
172                         print(RuntimeError('Changed session ID %s' % name))
173                     self.sessions[name] = value
174 
175         # find all forms and formkeys in page
176         self.forms = {}
177         for match in FORM_REGEX.finditer(to_native(self.text)):
178             self.forms[match.group('formname')] = match.group('formkey')
179 
180         # log this request
181         self.history.append((self.method, self.url, self.status, self.time))
182 
183 
184 def test_web2py_registration_and_login():
185     # from gluon.contrib.webclient import WebClient
186     # start a web2py instance for testing
187 
188     client = WebClient('http://127.0.0.1:8000/welcome/default/')
189     client.get('index')
190 
191     # register
192     data = dict(first_name='Homer',
193                 last_name='Simpson',
194                 email='homer@web2py.com',
195                 password='test',
196                 password_two='test',
197                 _formname='register')
198     client.post('user/register', data=data)
199 
200     # logout
201     client.get('user/logout')
202 
203     # login
204     data = dict(email='homer@web2py.com',
205                 password='test',
206                 _formname='login')
207     client.post('user/login', data=data)
208 
209     # check registration and login were successful
210     client.get('user/profile')
211     assert 'Welcome Homer' in client.text
212 
213     # print some variables
214     print('\nsessions:\n', client.sessions)
215     print('\nheaders:\n', client.headers)
216     print('\ncookies:\n', client.cookies)
217     print('\nforms:\n', client.forms)
218     print()
219     for method, url, status, t in client.history:
220         print(method, url, status, t)
221 
222 if __name__ == '__main__':
223     test_web2py_registration_and_login()
224
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/gluon/contrib/webclient.py b/gluon/contrib/webclient.py
--- a/gluon/contrib/webclient.py
+++ b/gluon/contrib/webclient.py
@@ -121,7 +121,7 @@
                 self.method = 'POST' if method=='auto' else method
                 # if there is only one form, set _formname automatically
                 if not '_formname' in data and len(self.forms) == 1:
-                    data['_formname'] = self.forms.keys()[0]
+                    data['_formname'] = next(iter(self.forms.keys())) # Use the first key
 
                 # if there is no formkey but it is known, set it
                 if '_formname' in data and not '_formkey' in data and \

{"golden_diff": "diff --git a/gluon/contrib/webclient.py b/gluon/contrib/webclient.py\n--- a/gluon/contrib/webclient.py\n+++ b/gluon/contrib/webclient.py\n@@ -121,7 +121,7 @@\n                 self.method = 'POST' if method=='auto' else method\n                 # if there is only one form, set _formname automatically\n                 if not '_formname' in data and len(self.forms) == 1:\n-                    data['_formname'] = self.forms.keys()[0]\n+                    data['_formname'] = next(iter(self.forms.keys())) # Use the first key\n \n                 # if there is no formkey but it is known, set it\n                 if '_formname' in data and not '_formkey' in data and \\\n", "issue": "Python 3 compatibility fix\nhttps://github.com/web2py/web2py/blob/master/gluon/contrib/webclient.py#L124 should be `data['_formname'] = list(self.forms.keys())[0]` to avoid `TypeError: 'dict_keys' object does not support indexing` when this is executing under Python 3.\n", "before_files": [{"content": "\"\"\"\nDeveloped by Massimo Di Pierro\nReleased under the web2py license (LGPL)\n\nIt an interface on top of urllib2 which simplifies scripting of http requests\nmostly for testing purposes\n\n- customizable\n- supports basic auth\n- supports cookies\n- supports session cookies (tested with web2py sessions)\n- detects broken session\n- detects web2py form postbacks and handles formname and formkey\n- detects web2py tickets\n\nSome examples at the bottom.\n\"\"\"\nfrom __future__ import print_function\nfrom gluon._compat import urllib2, cookielib, iteritems, to_native, urlencode, to_bytes\nimport re\nimport time\n\n\nDEFAULT_HEADERS = {\n    'user-agent': 'Mozilla/4.0',  # some servers are picky\n    'accept-language': 'en',\n}\n\nFORM_REGEX = re.compile('(\\<input name\\=\"_formkey\" type\\=\"hidden\" value\\=\"(?P<formkey>.+?)\" \\/\\>)?\\<input name\\=\"_formname\" type\\=\"hidden\" value\\=\"(?P<formname>.+?)\" \\/\\>')\n\nSESSION_REGEX = 'session_id_(?P<name>.+)'\n\n\nclass WebClient(object):\n\n    def __init__(self,\n                 app='',\n                 postbacks=True,\n                 default_headers=DEFAULT_HEADERS,\n                 session_regex=SESSION_REGEX):\n        self.app = app\n        self.postbacks = postbacks\n        self.forms = {}\n        self.history = []\n        self.cookies = {}\n        self.cookiejar = cookielib.CookieJar()\n        self.default_headers = default_headers\n        self.sessions = {}\n        self.session_regex = session_regex and re.compile(session_regex)\n        self.headers = {}\n\n    def _parse_headers_in_cookies(self):\n        self.cookies = {}\n        if 'set-cookie' in self.headers:\n            for item in self.headers['set-cookie'].split(','):\n                cookie = item[:item.find(';')]\n                pos = cookie.find('=')\n                key = cookie[:pos]\n                value = cookie[pos+1:]\n                self.cookies[key.strip()] = value.strip()\n\n    def get(self, url, cookies=None, headers=None, auth=None):\n        return self.post(url, data=None, cookies=cookies,\n                         headers=headers, method='GET')\n\n    def post(self, url, data=None, cookies=None,\n             headers=None, auth=None, method='auto'):\n        self.url = self.app + url\n\n        # if this POST form requires a postback do it\n        if data and '_formname' in data and self.postbacks and \\\n                self.history and self.history[-1][1] != self.url:\n            # to bypass the web2py CSRF need to get formkey\n            # before submitting the form\n            self.get(url, cookies=cookies, headers=headers, auth=auth)\n\n        # unless cookies are specified, recycle cookies\n        if cookies is None:\n            cookies = self.cookies\n        cookies = cookies or {}\n        headers = headers or {}\n\n        args = [\n            urllib2.HTTPCookieProcessor(self.cookiejar),\n            urllib2.HTTPHandler(debuglevel=0)\n            ]\n        # if required do basic auth\n        if auth:\n            auth_handler = urllib2.HTTPBasicAuthHandler()\n            auth_handler.add_password(**auth)\n            args.append(auth_handler)\n\n        opener = urllib2.build_opener(*args)\n\n        # copy headers from dict to list of key,value\n        headers_list = []\n        for key, value in iteritems(self.default_headers):\n            if not key in headers:\n                headers[key] = value\n        for key, value in iteritems(headers):\n            if isinstance(value, (list, tuple)):\n                for v in value:\n                    headers_list.append((key, v))\n            else:\n                headers_list.append((key, value))\n\n        # move cookies to headers\n        for key, value in iteritems(cookies):\n            headers_list.append(('Cookie', '%s=%s' % (key, value)))\n\n        # add headers to request\n        for key, value in headers_list:\n            opener.addheaders.append((key, str(value)))\n\n        # assume everything is ok and make http request\n        error = None\n        try:\n            if isinstance(data, str):\n                self.method = 'POST' if method=='auto' else method\n            elif isinstance(data, dict):\n                self.method = 'POST' if method=='auto' else method\n                # if there is only one form, set _formname automatically\n                if not '_formname' in data and len(self.forms) == 1:\n                    data['_formname'] = self.forms.keys()[0]\n\n                # if there is no formkey but it is known, set it\n                if '_formname' in data and not '_formkey' in data and \\\n                        data['_formname'] in self.forms:\n                    data['_formkey'] = self.forms[data['_formname']]\n\n                # time the POST request\n                data = urlencode(data, doseq=True)\n            else:\n                self.method = 'GET' if method=='auto' else method\n                data = None\n            t0 = time.time()\n            self.response = opener.open(self.url, to_bytes(data))\n            self.time = time.time() - t0\n        except urllib2.HTTPError as er:\n            error = er\n            # catch HTTP errors\n            self.time = time.time() - t0\n            self.response = er\n\n        if hasattr(self.response, 'getcode'):\n            self.status = self.response.getcode()\n        else:#python2.5\n            self.status = None\n\n        self.text = to_native(self.response.read())\n        # In PY3 self.response.headers are case sensitive\n        self.headers = dict()\n        for h in self.response.headers:\n            self.headers[h.lower()] = self.response.headers[h]\n\n        # treat web2py tickets as special types of errors\n        if error is not None:\n            if 'web2py_error' in self.headers:\n                raise RuntimeError(self.headers['web2py_error'])\n            else:\n                raise error\n\n        self._parse_headers_in_cookies()\n\n        # check is a new session id has been issued, symptom of broken session\n        if self.session_regex is not None:\n            for cookie, value in iteritems(self.cookies):\n                match = self.session_regex.match(cookie)\n                if match:\n                    name = match.group('name')\n                    if name in self.sessions and self.sessions[name] != value:\n                        print(RuntimeError('Changed session ID %s' % name))\n                    self.sessions[name] = value\n\n        # find all forms and formkeys in page\n        self.forms = {}\n        for match in FORM_REGEX.finditer(to_native(self.text)):\n            self.forms[match.group('formname')] = match.group('formkey')\n\n        # log this request\n        self.history.append((self.method, self.url, self.status, self.time))\n\n\ndef test_web2py_registration_and_login():\n    # from gluon.contrib.webclient import WebClient\n    # start a web2py instance for testing\n\n    client = WebClient('http://127.0.0.1:8000/welcome/default/')\n    client.get('index')\n\n    # register\n    data = dict(first_name='Homer',\n                last_name='Simpson',\n                email='homer@web2py.com',\n                password='test',\n                password_two='test',\n                _formname='register')\n    client.post('user/register', data=data)\n\n    # logout\n    client.get('user/logout')\n\n    # login\n    data = dict(email='homer@web2py.com',\n                password='test',\n                _formname='login')\n    client.post('user/login', data=data)\n\n    # check registration and login were successful\n    client.get('user/profile')\n    assert 'Welcome Homer' in client.text\n\n    # print some variables\n    print('\\nsessions:\\n', client.sessions)\n    print('\\nheaders:\\n', client.headers)\n    print('\\ncookies:\\n', client.cookies)\n    print('\\nforms:\\n', client.forms)\n    print()\n    for method, url, status, t in client.history:\n        print(method, url, status, t)\n\nif __name__ == '__main__':\n    test_web2py_registration_and_login()\n", "path": "gluon/contrib/webclient.py"}], "after_files": [{"content": "\"\"\"\nDeveloped by Massimo Di Pierro\nReleased under the web2py license (LGPL)\n\nIt an interface on top of urllib2 which simplifies scripting of http requests\nmostly for testing purposes\n\n- customizable\n- supports basic auth\n- supports cookies\n- supports session cookies (tested with web2py sessions)\n- detects broken session\n- detects web2py form postbacks and handles formname and formkey\n- detects web2py tickets\n\nSome examples at the bottom.\n\"\"\"\nfrom __future__ import print_function\nfrom gluon._compat import urllib2, cookielib, iteritems, to_native, urlencode, to_bytes\nimport re\nimport time\n\n\nDEFAULT_HEADERS = {\n    'user-agent': 'Mozilla/4.0',  # some servers are picky\n    'accept-language': 'en',\n}\n\nFORM_REGEX = re.compile('(\\<input name\\=\"_formkey\" type\\=\"hidden\" value\\=\"(?P<formkey>.+?)\" \\/\\>)?\\<input name\\=\"_formname\" type\\=\"hidden\" value\\=\"(?P<formname>.+?)\" \\/\\>')\n\nSESSION_REGEX = 'session_id_(?P<name>.+)'\n\n\nclass WebClient(object):\n\n    def __init__(self,\n                 app='',\n                 postbacks=True,\n                 default_headers=DEFAULT_HEADERS,\n                 session_regex=SESSION_REGEX):\n        self.app = app\n        self.postbacks = postbacks\n        self.forms = {}\n        self.history = []\n        self.cookies = {}\n        self.cookiejar = cookielib.CookieJar()\n        self.default_headers = default_headers\n        self.sessions = {}\n        self.session_regex = session_regex and re.compile(session_regex)\n        self.headers = {}\n\n    def _parse_headers_in_cookies(self):\n        self.cookies = {}\n        if 'set-cookie' in self.headers:\n            for item in self.headers['set-cookie'].split(','):\n                cookie = item[:item.find(';')]\n                pos = cookie.find('=')\n                key = cookie[:pos]\n                value = cookie[pos+1:]\n                self.cookies[key.strip()] = value.strip()\n\n    def get(self, url, cookies=None, headers=None, auth=None):\n        return self.post(url, data=None, cookies=cookies,\n                         headers=headers, method='GET')\n\n    def post(self, url, data=None, cookies=None,\n             headers=None, auth=None, method='auto'):\n        self.url = self.app + url\n\n        # if this POST form requires a postback do it\n        if data and '_formname' in data and self.postbacks and \\\n                self.history and self.history[-1][1] != self.url:\n            # to bypass the web2py CSRF need to get formkey\n            # before submitting the form\n            self.get(url, cookies=cookies, headers=headers, auth=auth)\n\n        # unless cookies are specified, recycle cookies\n        if cookies is None:\n            cookies = self.cookies\n        cookies = cookies or {}\n        headers = headers or {}\n\n        args = [\n            urllib2.HTTPCookieProcessor(self.cookiejar),\n            urllib2.HTTPHandler(debuglevel=0)\n            ]\n        # if required do basic auth\n        if auth:\n            auth_handler = urllib2.HTTPBasicAuthHandler()\n            auth_handler.add_password(**auth)\n            args.append(auth_handler)\n\n        opener = urllib2.build_opener(*args)\n\n        # copy headers from dict to list of key,value\n        headers_list = []\n        for key, value in iteritems(self.default_headers):\n            if not key in headers:\n                headers[key] = value\n        for key, value in iteritems(headers):\n            if isinstance(value, (list, tuple)):\n                for v in value:\n                    headers_list.append((key, v))\n            else:\n                headers_list.append((key, value))\n\n        # move cookies to headers\n        for key, value in iteritems(cookies):\n            headers_list.append(('Cookie', '%s=%s' % (key, value)))\n\n        # add headers to request\n        for key, value in headers_list:\n            opener.addheaders.append((key, str(value)))\n\n        # assume everything is ok and make http request\n        error = None\n        try:\n            if isinstance(data, str):\n                self.method = 'POST' if method=='auto' else method\n            elif isinstance(data, dict):\n                self.method = 'POST' if method=='auto' else method\n                # if there is only one form, set _formname automatically\n                if not '_formname' in data and len(self.forms) == 1:\n                    data['_formname'] = next(iter(self.forms.keys())) # Use the first key\n\n                # if there is no formkey but it is known, set it\n                if '_formname' in data and not '_formkey' in data and \\\n                        data['_formname'] in self.forms:\n                    data['_formkey'] = self.forms[data['_formname']]\n\n                # time the POST request\n                data = urlencode(data, doseq=True)\n            else:\n                self.method = 'GET' if method=='auto' else method\n                data = None\n            t0 = time.time()\n            self.response = opener.open(self.url, to_bytes(data))\n            self.time = time.time() - t0\n        except urllib2.HTTPError as er:\n            error = er\n            # catch HTTP errors\n            self.time = time.time() - t0\n            self.response = er\n\n        if hasattr(self.response, 'getcode'):\n            self.status = self.response.getcode()\n        else:#python2.5\n            self.status = None\n\n        self.text = to_native(self.response.read())\n        # In PY3 self.response.headers are case sensitive\n        self.headers = dict()\n        for h in self.response.headers:\n            self.headers[h.lower()] = self.response.headers[h]\n\n        # treat web2py tickets as special types of errors\n        if error is not None:\n            if 'web2py_error' in self.headers:\n                raise RuntimeError(self.headers['web2py_error'])\n            else:\n                raise error\n\n        self._parse_headers_in_cookies()\n\n        # check is a new session id has been issued, symptom of broken session\n        if self.session_regex is not None:\n            for cookie, value in iteritems(self.cookies):\n                match = self.session_regex.match(cookie)\n                if match:\n                    name = match.group('name')\n                    if name in self.sessions and self.sessions[name] != value:\n                        print(RuntimeError('Changed session ID %s' % name))\n                    self.sessions[name] = value\n\n        # find all forms and formkeys in page\n        self.forms = {}\n        for match in FORM_REGEX.finditer(to_native(self.text)):\n            self.forms[match.group('formname')] = match.group('formkey')\n\n        # log this request\n        self.history.append((self.method, self.url, self.status, self.time))\n\n\ndef test_web2py_registration_and_login():\n    # from gluon.contrib.webclient import WebClient\n    # start a web2py instance for testing\n\n    client = WebClient('http://127.0.0.1:8000/welcome/default/')\n    client.get('index')\n\n    # register\n    data = dict(first_name='Homer',\n                last_name='Simpson',\n                email='homer@web2py.com',\n                password='test',\n                password_two='test',\n                _formname='register')\n    client.post('user/register', data=data)\n\n    # logout\n    client.get('user/logout')\n\n    # login\n    data = dict(email='homer@web2py.com',\n                password='test',\n                _formname='login')\n    client.post('user/login', data=data)\n\n    # check registration and login were successful\n    client.get('user/profile')\n    assert 'Welcome Homer' in client.text\n\n    # print some variables\n    print('\\nsessions:\\n', client.sessions)\n    print('\\nheaders:\\n', client.headers)\n    print('\\ncookies:\\n', client.cookies)\n    print('\\nforms:\\n', client.forms)\n    print()\n    for method, url, status, t in client.history:\n        print(method, url, status, t)\n\nif __name__ == '__main__':\n    test_web2py_registration_and_login()\n", "path": "gluon/contrib/webclient.py"}]}