[CE-489] Fixed Code Format Issue

The updated of flake8 will lead to failure of 'make check',
because some of the existed codes are unable to pass the
extended format check, this patch make the following changes
for fixing this problem:
 1. Ignore flake8 W504(break after binary operator) checking
 2. Ignore flake8 W605(invalid escape sequence) checking
 3. Remove some unused variable

CE-489 #done

Change-Id: Ied16719faa8a2caf0bd4dfabd72a0e095cf2e5ea
Signed-off-by: luke <jiahaochen1993@gmail.com>

src/agent/vsphere/host.py

@@ -44,7 +44,7 @@ def create(self, vcip, username, pwd, port, params, hid):
             connection = si.RetrieveContent()
             vc_resources = params.get(VCENTER)
 
-        except Exception as e:
+        except Exception:
             error_msg = (
                 "Cannot complete login due"
                 "to an incorrect user name or password."

src/agent/vsphere/host_operations.py

@@ -437,6 +437,6 @@ def check_isport_open(self, vmip, vmport, timeout=300):
                 timeout -= 5
                 sk.connect((vmip, vmport))
                 return True
-            except Exception as e:
+            except Exception:
                 pass
         return False

src/common/stringvalidator.py

@@ -42,7 +42,7 @@ def validate(self, input, checks=[], log=False):
                         return False
 
             except Exception as e:
-                raise
+                raise e
 
         return True if not fail else results
 
@@ -55,7 +55,7 @@ def _check_is_numeric(self, input):
         try:
             float(input)
             return True
-        except Exception as e:
+        except Exception:
             return False
 
     def _check_is_alpha(self, input):
@@ -71,14 +71,14 @@ def _check_is_integer(self, input):
         try:
             int(input)
             return True
-        except Exception as e:
+        except Exception:
             return False
 
     def _check_is_float(self, input):
         """Check if a given string is float"""
         try:
             return True if str(float(input)) == input else False
-        except Exception as e:
+        except Exception:
             return False
 
     def _check_longer_than(self, input, args):

tox.ini

@@ -21,4 +21,4 @@ basepython = python3
 skip_install = true
 deps = flake8
        -r{toxinidir}/src/requirements.txt
-commands = flake8 --ignore=E402,F401 {toxinidir}/src
+commands = flake8 --ignore=E402,F401,W504,W605 {toxinidir}/src