How can I use itertools to simplify this nested for loop?
# pytest file:
def get_test_cases():
with open("file_path.yml", "r", encoding="utf-8") as index_file:
data = yaml.safe_load(index_file)
for vendor_dict in data:
for vendor_name, class_list in vendor_dict.items():
for class_dict in class_list:
for class_name, method_list in class_dict.items():
for method_dict in method_list:
for function, test_list in method_dict.items():
for test_case in test_list:
yield vendor_name, class_name, function, test_case
@pytest.mark.parametrize("iteration", get_test_cases())
def test_network(iteration, monkeypatch):
"""Performs pytest using info provided from test case"""
(vendor_name, class_name, function, test_case) = iteration
# Use data above to perform pytest
# Code omitted
Sample Data is in YAML:
# YAML file:
- cisco:
- CiscoClass:
- get_interface_stats:
- test_description: "test interface stats"
function_input: "Gig1/1/1"
expected_output: "show interfaces Gig1/1/1"
- juniper:
- JuniperClass:
- get_vlan_info:
- test_description: "test get_vlan_info"
function_input: "10"
expected_output: "show vlan 10"
Explanation
The YAML file contains parameters uses for building test cases. We have a block of test cases for Cisco, and other test cases for Juniper. So the structure is this vendor --> name of class --> function --> test case data
Function get_test_cases in my pytest file will load the YAML file contents, and then iterates through the contents, and yield data for each test case. Function test_network consumes this data, and performs the actual testing.
I am trying to find an alternative to the nested for loops so that I can raise my pylint rating... if this is even possible.
CodePudding user response:
You could try the following to make it a bit compacter:
def testcases(data, level=0):
if level == 3:
for case in data:
yield (case,)
else:
for record in data:
for name in record:
for case in testcases(record[name], level 1):
yield (name,) case
or
def testcases(data, level=0):
if level == 6:
for case in data:
yield (case,)
elif level % 2 == 0:
for record in data:
yield from testcases(record, level 1)
else:
for name, records in data.items():
for case in testcases(records, level 1):
yield (name,) case
and then
def get_test_cases():
with open("file_path.yml", "r", encoding="utf-8") as index_file:
data = yaml.safe_load(index_file)
yield from testcases(data)
With your sample file this
for case in get_test_cases():
print(case)
does produce
('cisco', 'CiscoClass', 'get_interface_stats', {'test_description': 'test interface stats', 'function_input': 'Gig1/1/1', 'expected_output': 'show interfaces Gig1/1/1'})
('juniper', 'JuniperClass', 'get_vlan_info', {'test_description': 'test get_vlan_info', 'function_input': '10', 'expected_output': 'show vlan 10'})