diff options
| -rw-r--r-- | Doc/library/collections.rst | 14 | ||||
| -rw-r--r-- | Lib/collections.py | 2 |
2 files changed, 8 insertions, 8 deletions
diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst index 1e213fb..6b02576 100644 --- a/Doc/library/collections.rst +++ b/Doc/library/collections.rst @@ -364,8 +364,8 @@ they add the ability to access fields by name instead of position index. method which lists the tuple contents in a ``name=value`` format. The *fieldnames* are a single string with each fieldname separated by whitespace - and/or commas (for example 'x y' or 'x, y'). Alternatively, *fieldnames* - can be a sequence of strings (such as ['x', 'y']). + and/or commas, for example ``'x y'`` or ``'x, y'``. Alternatively, *fieldnames* + can be a sequence of strings such as ``['x', 'y']``. Any valid Python identifier may be used for a fieldname except for names starting with an underscore. Valid identifiers consist of letters, digits, @@ -373,7 +373,7 @@ they add the ability to access fields by name instead of position index. a :mod:`keyword` such as *class*, *for*, *return*, *global*, *pass*, *print*, or *raise*. - If *verbose* is true, will print the class definition. + If *verbose* is true, the class definition is printed just before being built. Named tuple instances do not have per-instance dictionaries, so they are lightweight and require no more memory than regular tuples. @@ -518,16 +518,16 @@ a fixed-width print format:: ... def hypot(self): ... return (self.x ** 2 + self.y ** 2) ** 0.5 ... def __str__(self): - ... return 'Point: x=%6.3f y=%6.3f hypot=%6.3f' % (self.x, self.y, self.hypot) + ... return 'Point: x=%6.3f y=%6.3f hypot=%6.3f' % (self.x, self.y, self.hypot) >>> for p in Point(3, 4), Point(14, 5/7.): ... print p - Point: x= 3.000 y= 4.000 hypot= 5.000 - Point: x=14.000 y= 0.714 hypot=14.018 + Point: x= 3.000 y= 4.000 hypot= 5.000 + Point: x=14.000 y= 0.714 hypot=14.018 Another use for subclassing is to replace performance critcal methods with -faster versions that bypass error-checking and that localize variable access:: +faster versions that bypass error-checking:: class Point(namedtuple('Point', 'x y')): __slots__ = () diff --git a/Lib/collections.py b/Lib/collections.py index 267c39f..b03a733 100644 --- a/Lib/collections.py +++ b/Lib/collections.py @@ -123,7 +123,7 @@ if __name__ == '__main__': def hypot(self): return (self.x ** 2 + self.y ** 2) ** 0.5 def __str__(self): - return 'Point: x=%6.3f y=%6.3f hypot=%6.3f' % (self.x, self.y, self.hypot) + return 'Point: x=%6.3f y=%6.3f hypot=%6.3f' % (self.x, self.y, self.hypot) for p in Point(3, 4), Point(14, 5/7.): print p |