Fix Python3 RuntimeError - dictionary changed size during iteration (#…

…6646)

Summary:
Fix Python3 RuntimeError - dictionary changed size during iteration

What is the motivation for this PR?
Python3 migration: In Python3, you cannot add/remove elements in a dictionary while iterating through it.

How did you do it?
1. Use copy(). This way you iterate over the original dictionary fields and on the fly can change the desired dict.
2. Fix pre-commit issues.

How did you verify/test it?
Both Python2 and Python3 can run bgp/test_bgp_facts.py successfully.

tests/common/plugins/conditional_mark/__init__.py

@@ -113,7 +113,7 @@ def read_asic_name(hwsku):
         with open(asic_name_file) as f:
             asic_name = yaml.safe_load(f)
 
-        for key, value in asic_name.items():
+        for key, value in asic_name.copy().items():
             if ('td' not in key) and ('th' not in key) and ('spc' not in key):
                 asic_name.pop(key)
 
@@ -123,9 +123,10 @@ def read_asic_name(hwsku):
 
         return "unknown"
 
-    except IOError as e:
+    except IOError:
         return None
 
+
 def load_dut_basic_facts(inv_name, dut_name):
     """Run 'ansible -m dut_basic_facts' command to get some basic DUT facts.
 
@@ -155,6 +156,7 @@ def load_dut_basic_facts(inv_name, dut_name):
 
     return results
 
+
 def get_basic_facts(session):
     testbed_name = session.config.option.testbed
 
@@ -209,6 +211,7 @@ def load_minigraph_facts(inv_name, dut_name):
 
     return results
 
+
 def load_config_facts(inv_name, dut_name):
     """Run 'ansible -m config_facts -a 'host={{hostname}} source='persistent' ' command to get some basic config facts.
 
@@ -225,7 +228,8 @@ def load_config_facts(inv_name, dut_name):
     logger.info('Getting config basic facts')
     try:
         # get config basic faces
-        ansible_cmd = ['ansible', '-m', 'config_facts', '-i', '../ansible/{}'.format(inv_name), '{}'.format(dut_name), '-a', 'host={} source=\'persistent\''.format(dut_name)]
+        ansible_cmd = ['ansible', '-m', 'config_facts', '-i', '../ansible/{}'.format(inv_name),
+                       '{}'.format(dut_name), '-a', 'host={} source=\'persistent\''.format(dut_name)]
         raw_output = subprocess.check_output(ansible_cmd).decode('utf-8')
         logger.debug('raw config basic facts:\n{}'.format(raw_output))
         output_fields = raw_output.split('SUCCESS =>', 1)
@@ -239,6 +243,7 @@ def load_config_facts(inv_name, dut_name):
 
     return results
 
+
 def load_switch_capabilities_facts(inv_name, dut_name):
     """Run 'ansible -m switch_capabilities_facts' command to get some basic config facts.
 
@@ -267,6 +272,7 @@ def load_switch_capabilities_facts(inv_name, dut_name):
 
     return results
 
+
 def load_console_facts(inv_name, dut_name):
     """Run 'ansible -m console_facts' command to get some basic console facts.
 
@@ -295,6 +301,7 @@ def load_console_facts(inv_name, dut_name):
 
     return results
 
+
 def load_basic_facts(session):
     """Load some basic facts that can be used in condition statement evaluation.
 
@@ -446,15 +453,15 @@ def evaluate_condition(dynamic_update_skip_reason, mark_details, condition, basi
         if condition_result and dynamic_update_skip_reason:
             mark_details['reason'].append(condition)
         return condition_result
-    except Exception as e:
+    except Exception:
         logger.error('Failed to evaluate condition, raw_condition={}, condition_str={}'.format(
             condition,
             condition_str))
         return False
 
 
-def evaluate_conditions(dynamic_update_skip_reason, mark_details, conditions, basic_facts, \
-    conditions_logical_operator, session):
+def evaluate_conditions(dynamic_update_skip_reason, mark_details, conditions, basic_facts,
+                        conditions_logical_operator, session):
     """Evaluate all the condition strings.
 
     Evaluate a single condition or multiple conditions. If multiple conditions are supplied, apply AND or OR
@@ -478,9 +485,11 @@ def evaluate_conditions(dynamic_update_skip_reason, mark_details, conditions, ba
     if isinstance(conditions, list):
         # Apply 'AND' or 'OR' operation to list of conditions based on conditions_logical_operator(by default 'AND')
         if conditions_logical_operator == 'OR':
-            return any([evaluate_condition(dynamic_update_skip_reason, mark_details, c, basic_facts, session) for c in conditions])
+            return any([evaluate_condition(dynamic_update_skip_reason, mark_details, c, basic_facts, session)
+                        for c in conditions])
         else:
-            return all([evaluate_condition(dynamic_update_skip_reason, mark_details, c, basic_facts, session) for c in conditions])
+            return all([evaluate_condition(dynamic_update_skip_reason, mark_details, c, basic_facts, session)
+                        for c in conditions])
     else:
         if conditions is None or conditions.strip() == '':
             return True