git-p4: compare to singletons with "is" and "is not"

PEP8 recommends that comparisons with singletons such as None should be
done with "is" and "is not", and never equality operators.

This guideline is described here:
https://www.python.org/dev/peps/pep-0008/#programming-recommendations

Signed-off-by: Joel Holdsworth <jholdsworth@nvidia.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-p4.py b/git-p4.py
index a25adc8baee6e9a5e5db4cd649d8a781bd942f3e..2f2450f7d9b62ce7452bc539dceefd219fe8f55c 100755 (executable)
--- a/git-p4.py
+++ b/git-p4.py
@@ -857,7 +857,7 @@ def p4Where(depotPath):
             if data[:space] == depotPath:
                 output = entry
                 break
-    if output == None:
+    if output is None:
         return ""
     if output["code"] == "error":
         return ""
@@ -879,7 +879,7 @@ def currentGitBranch():
 
 
 def isValidGitDir(path):
-    return git_dir(path) != None
+    return git_dir(path) is not None
 
 
 def parseRevision(ref):
@@ -4425,7 +4425,7 @@ def main():
     global verbose
     verbose = cmd.verbose
     if cmd.needsGit:
-        if cmd.gitdir == None:
+        if cmd.gitdir is None:
             cmd.gitdir = os.path.abspath(".git")
             if not isValidGitDir(cmd.gitdir):
                 # "rev-parse --git-dir" without arguments will try $PWD/.git