Changes between Version 4 and Version 5 of PythonPort/Design

Timestamp:

Oct 15, 2007, 3:24:23 PM (18 years ago)

Author:

Daniel Wallin

Comment:

Python code style guidelines

PythonPort/Design

@@ -19 +19 @@
   * Using of the property_set class. Unless required for compatibility with Jamfiles, we'll be using property_set in all remaining     cases where raw property list is used now.
   * Path normalization. Jam code uses 'path.make' and 'path.native' to convert from native to normalized pathnames. Since Python     has robust path manipulation functions, this logic will be dropped -- we'll use os.path everywhere.
-      
+
+== Python style ==
+
+Please try to adhere to the Python style guidelines at:
+http://www.python.org/dev/peps/pep-0008/.
+
+The current code base breaks against a lot of these rules. If you encounter any
+of these problems while working on the code, please fix them as you go.
+
+The most common problems are extraneous whitespace.
+
+'''NO'''
+{{{
+__declared_subfeature [str (t, name)] = True
+m = __re__before_first_dash.match (toolset)
+}}}
+
+'''YES'''
+{{{
+__declared_subfeature[str(t, name)] = True
+m = __re__before_first_dash.match(toolset)
+}}}
+
+This is bad style. No whitespace should be used before brackets or parentheses.
+Sometimes whitespace is also used inside braces:
+
+'''NO'''
+{{{
+{ 'foo': 'bar' }
+}}}
+
+'''YES'''
+{{{
+{'foo': 'bar'}
+}}}
+
+These whitespace should also be removed. Whitespace should also not be present
+in argument defaults:
+
+'''NO'''
+{{{
+def __init__(self, name, project, manager = None):
+}}}
+
+'''YES'''
+{{{
+def __init__(self, name, project, manager=None):
+}}}
+
+Another common issue is using `has_key` to determine if a key is present
+in a dictionary. Instead operator `in` should be used:
+
+'''NO'''
+{{{
+if foo.has_key('bar')
+}}}
+
+'''YES'''
+{{{
+if 'bar' in foo:
+}}}
+
+Don't use [] as an argument default without making absolutely sure
+the argument isn't mutated inside the function. Instead, use something
+like:
+
+{{{
+def foo(x=None):
+    if x is None:
+        x = []
+}}}
+
+Don't use `len()` to test for empty sequences:
+
+'''NO'''
+{{{
+if len(x):
+if not len(x):
+}}}
+
+'''YES'''
+{{{
+if x:
+if not x:
+}}}
+
+
 == Design: Physical structure ==