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-rw-r--r--Doc/faq/programming.rst39
1 files changed, 19 insertions, 20 deletions
diff --git a/Doc/faq/programming.rst b/Doc/faq/programming.rst
index 4578280..d83833d 100644
--- a/Doc/faq/programming.rst
+++ b/Doc/faq/programming.rst
@@ -353,7 +353,7 @@ functions), e.g.::
>>> squares = []
>>> for x in range(5):
- ... squares.append(lambda: x**2)
+ ... squares.append(lambda: x**2)
This gives you a list that contains 5 lambdas that calculate ``x**2``. You
might expect that, when called, they would return, respectively, ``0``, ``1``,
@@ -380,7 +380,7 @@ lambdas, so that they don't rely on the value of the global ``x``::
>>> squares = []
>>> for x in range(5):
- ... squares.append(lambda n=x: n**2)
+ ... squares.append(lambda n=x: n**2)
Here, ``n=x`` creates a new variable ``n`` local to the lambda and computed
when the lambda is defined so that it has the same value that ``x`` had at
@@ -699,7 +699,7 @@ desired effect in a number of ways.
args['a'] = 'new-value' # args is a mutable dictionary
args['b'] = args['b'] + 1 # change it in-place
- args = {'a':' old-value', 'b': 99}
+ args = {'a': 'old-value', 'b': 99}
func3(args)
print args['a'], args['b']
@@ -815,16 +815,15 @@ Essentially, assignment always binds a name to a value; The same is true of
``def`` and ``class`` statements, but in that case the value is a
callable. Consider the following code::
- class A:
- pass
-
- B = A
-
- a = B()
- b = a
- print b
+ >>> class A:
+ ... pass
+ ...
+ >>> B = A
+ >>> a = B()
+ >>> b = a
+ >>> print b
<__main__.A instance at 0x16D07CC>
- print a
+ >>> print a
<__main__.A instance at 0x16D07CC>
Arguably the class has a name: even though it is bound to two names and invoked
@@ -1209,7 +1208,7 @@ How do I iterate over a sequence in reverse order?
Use the :func:`reversed` built-in function, which is new in Python 2.4::
for x in reversed(sequence):
- ... # do something with x...
+ ... # do something with x ...
This won't touch your original sequence, but build a new copy with reversed
order to iterate over.
@@ -1217,7 +1216,7 @@ order to iterate over.
With Python 2.3, you can use an extended slice syntax::
for x in sequence[::-1]:
- ... # do something with x...
+ ... # do something with x ...
How do you remove duplicates from a list?
@@ -1552,7 +1551,7 @@ A method is a function on some object ``x`` that you normally call as
definition::
class C:
- def meth (self, arg):
+ def meth(self, arg):
return arg * 2 + self.attribute
@@ -1585,9 +1584,9 @@ that does something::
def search(obj):
if isinstance(obj, Mailbox):
- # ... code to search a mailbox
+ ... # code to search a mailbox
elif isinstance(obj, Document):
- # ... code to search a document
+ ... # code to search a document
elif ...
A better approach is to define a ``search()`` method on all the classes and just
@@ -1595,11 +1594,11 @@ call it::
class Mailbox:
def search(self):
- # ... code to search a mailbox
+ ... # code to search a mailbox
class Document:
def search(self):
- # ... code to search a document
+ ... # code to search a document
obj.search()
@@ -1656,7 +1655,7 @@ How do I call a method defined in a base class from a derived class that overrid
If you're using new-style classes, use the built-in :func:`super` function::
class Derived(Base):
- def meth (self):
+ def meth(self):
super(Derived, self).meth()
If you're using classic classes: For a class definition such as ``class