Fixing B006 - mutable objects as function argument defaults using None and if

Part-of: <https://gitlab.freedesktop.org/gstreamer/cerbero/-/merge_requests/1566>

13 files changed, 50 insertions, 19 deletions

diff --git a/cerbero/build/cookbook.py b/cerbero/build/cookbook.py
index 1499a5c2..86d84ee0 100644
--- a/cerbero/build/cookbook.py
+++ b/cerbero/build/cookbook.py
@@ -56,8 +56,8 @@ class RecipeStatus(object):
     @type file_hash: int
     """
 
-    def __init__(self, filepath, steps=[], needs_build=True, mtime=time.time(), built_version='', file_hash=0):
-        self.steps = steps
+    def __init__(self, filepath, steps=None, needs_build=True, mtime=time.time(), built_version='', file_hash=0):
+        self.steps = [] if steps is None else steps
         self.needs_build = needs_build
         self.mtime = mtime
         self.filepath = filepath
@@ -339,7 +339,11 @@ class CookBook(object):
         except IOError as ex:
             m.warning(_('Could not cache the CookBook: %s') % ex)
 
-    def _find_deps(self, recipe, state={}, ordered=[]):
+    def _find_deps(self, recipe, state=None, ordered=None):
+        if state is None:
+            state = {}
+        if ordered is None:
+            ordered = []
         if state.get(recipe, 'clean') == 'processed':
             return
         if state.get(recipe, 'clean') == 'in-progress':
diff --git a/cerbero/commands/__init__.py b/cerbero/commands/__init__.py
index c90080ae..863ae75f 100644
--- a/cerbero/commands/__init__.py
+++ b/cerbero/commands/__init__.py
@@ -31,8 +31,8 @@ class Command:
     doc = ''
     name = None
 
-    def __init__(self, arguments=[]):
-        self.arguments = arguments
+    def __init__(self, arguments=None):
+        self.arguments = [] if arguments is None else arguments
 
     def run(self, config, args):
         """The body of the command"""
diff --git a/cerbero/commands/bundlesource.py b/cerbero/commands/bundlesource.py
index 68ee7f89..588af02e 100644
--- a/cerbero/commands/bundlesource.py
+++ b/cerbero/commands/bundlesource.py
@@ -31,7 +31,7 @@ class BundleSource(Command):
     doc = N_('Bundle Source code of recipes and Cerbero')
     name = 'bundle-source'
 
-    def __init__(self, args=[]):
+    def __init__(self, args=None):
         args = [
             ArgparseArgument('bundlepackages', nargs='+', help=_('packages to bundle')),
             ArgparseArgument('--add-recipe', action='append', default=[], help=_('additional recipes to bundle')),
diff --git a/cerbero/commands/cache.py b/cerbero/commands/cache.py
index 7b04f695..b046d2e2 100644
--- a/cerbero/commands/cache.py
+++ b/cerbero/commands/cache.py
@@ -39,7 +39,9 @@ class BaseCache(Command):
     log_size = 10
     dry_run = False
 
-    def __init__(self, args=[]):
+    def __init__(self, args=None):
+        if args is None:
+            args = []
         args += [
             ArgparseArgument(
                 '--commit', action='store', type=str, default='HEAD', help='the commit to pick artifact from'
@@ -305,7 +307,9 @@ class GenCache(BaseCache):
     doc = N_('Generate build cache from current state.')
     name = 'gen-cache'
 
-    def __init__(self, args=[]):
+    def __init__(self, args=None):
+        if args is None:
+            args = []
         BaseCache.__init__(self, args)
 
     def create_tarball_tarfile(self, workdir, out_file, *in_files, exclude=None):
@@ -405,7 +409,9 @@ class UploadCache(BaseCache):
     doc = N_('Build build cache to external storage.')
     name = 'upload-cache'
 
-    def __init__(self, args=[]):
+    def __init__(self, args=None):
+        if args is None:
+            args = []
         BaseCache.__init__(self, args)
 
     def upload_dep(self, config, args, deps):
diff --git a/cerbero/commands/debugpackages.py b/cerbero/commands/debugpackages.py
index df50c5aa..ffa2a907 100644
--- a/cerbero/commands/debugpackages.py
+++ b/cerbero/commands/debugpackages.py
@@ -58,7 +58,9 @@ class DebugPackages(Command):
             m.message('Found duplicates files in packages:')
             m.message('%r' % duplicates)
 
-    def find_orphan_files(self, allfiles, prefix, excludes=[]):
+    def find_orphan_files(self, allfiles, prefix, excludes=None):
+        if excludes is None:
+            excludes = []
         cmd = ['find', '.', '-type', 'f']
         for x in excludes:
             cmd += ['(', '!', '-name', x, ')']
diff --git a/cerbero/commands/deps.py b/cerbero/commands/deps.py
index 91bea222..1386370e 100644
--- a/cerbero/commands/deps.py
+++ b/cerbero/commands/deps.py
@@ -66,7 +66,9 @@ class Deps(Command):
                 m.message(recipe.name)
         else:
 
-            def print_dep(cookbook, recipe, level=0, already_shown=[]):
+            def print_dep(cookbook, recipe, level=0, already_shown=None):
+                if already_shown is None:
+                    already_shown = []
                 m.message('%s%s' % (' ' * 3 * level, recipe.name))
                 already_shown.append(recipe)
                 for r in [cookbook.get_recipe(x) for x in recipe.list_deps()]:
diff --git a/cerbero/commands/fetch.py b/cerbero/commands/fetch.py
index db12d607..1a9171d8 100644
--- a/cerbero/commands/fetch.py
+++ b/cerbero/commands/fetch.py
@@ -40,7 +40,9 @@ NUMBER_OF_JOBS_IF_USED = 2 * determine_num_of_cpus()
 
 
 class Fetch(Command):
-    def __init__(self, args=[]):
+    def __init__(self, args=None):
+        if args is None:
+            args = []
         args.append(
             ArgparseArgument(
                 '--reset-rdeps',
diff --git a/cerbero/commands/graph.py b/cerbero/commands/graph.py
index 40bc5992..6f2ec301 100644
--- a/cerbero/commands/graph.py
+++ b/cerbero/commands/graph.py
@@ -101,7 +101,9 @@ class Graph(Command):
         shell.new_call(['dot', '-Tsvg', tmp.name, '-o', output])
         m.message('Dependency graph for %s generated at %s' % (name, output))
 
-    def _dot_gen(self, name, graph_type, already_parsed=[]):
+    def _dot_gen(self, name, graph_type, already_parsed=None):
+        if already_parsed is None:
+            already_parsed = []
         already_parsed.append(name)
         if graph_type == GraphType.RECIPE:
             deps = self.cookbook.get_recipe(name).list_deps()
diff --git a/cerbero/packages/ninja_syntax.py b/cerbero/packages/ninja_syntax.py
index 9289b85d..3f967b1b 100644
--- a/cerbero/packages/ninja_syntax.py
+++ b/cerbero/packages/ninja_syntax.py
@@ -214,13 +214,16 @@ def escape(string: str) -> str:
     return string.replace('$', '$$')
 
 
-def expand(string: str, vars: Dict[str, str], local_vars: Dict[str, str] = {}) -> str:
+def expand(string: str, vars: Dict[str, str], local_vars: Dict[str, str] = None) -> str:
     """Expand a string containing $vars as Ninja would.
 
     Note: doesn't handle the full Ninja variable syntax, but it's enough
     to make configure.py's use of it work.
     """
 
+    if local_vars is None:
+        local_vars = {}
+
     def exp(m: Match[str]) -> str:
         var = m.group(1)
         if var == '$':
diff --git a/cerbero/packages/packagesstore.py b/cerbero/packages/packagesstore.py
index bfd50d4d..563ce4c5 100644
--- a/cerbero/packages/packagesstore.py
+++ b/cerbero/packages/packagesstore.py
@@ -120,7 +120,11 @@ class PackagesStore(object):
         self._packages[package.name] = package
 
     def _list_metapackage_deps(self, metapackage):
-        def get_package_deps(package_name, visited=[], depslist=[]):
+        def get_package_deps(package_name, visited=None, depslist=None):
+            if visited is None:
+                visited = []
+            if depslist is None:
+                depslist = []
             if package_name in visited:
                 return
             visited.append(package_name)
diff --git a/cerbero/packages/windows/wix_on_ninja.py b/cerbero/packages/windows/wix_on_ninja.py
index 35f2ae16..151b191f 100644
--- a/cerbero/packages/windows/wix_on_ninja.py
+++ b/cerbero/packages/windows/wix_on_ninja.py
@@ -59,8 +59,8 @@ class Light(object):
 
     options = {}
 
-    def __init__(self, extra=[]):
-        self.options['extra'] = extra
+    def __init__(self, extra=None):
+        self.options['extra'] = [] if extra is None else extra
 
     def compile(self, writer: Writer, objects: list[str], msi_name: str, merge_module=False, implicit_deps=None):
         """
diff --git a/cerbero/tools/depstracker.py b/cerbero/tools/depstracker.py
index b7098805..582125e4 100644
--- a/cerbero/tools/depstracker.py
+++ b/cerbero/tools/depstracker.py
@@ -26,7 +26,11 @@ class RecursiveLister:
     def list_file_deps(self, prefix, path):
         raise NotImplementedError()
 
-    def find_deps(self, prefix, lib, state={}, ordered=[]):
+    def find_deps(self, prefix, lib, state=None, ordered=None):
+        if state is None:
+            state = {}
+        if ordered is None:
+            ordered = []
         if state.get(lib, 'clean') == 'processed':
             return
         if state.get(lib, 'clean') == 'in-progress':
diff --git a/cerbero/utils/shell.py b/cerbero/utils/shell.py
index c5b8af02..9c957b61 100644
--- a/cerbero/utils/shell.py
+++ b/cerbero/utils/shell.py
@@ -532,8 +532,10 @@ def find_files(pattern, prefix):
     return glob.glob(os.path.join(prefix, pattern))
 
 
-def prompt(message, options=[]):
+def prompt(message, options=None):
     """Prompts the user for input with the message and options"""
+    if options is None:
+        options = []
     if len(options) != 0:
         message = '%s [%s] ' % (message, '/'.join(options))
     res = input(message)