mirror of
https://github.com/kennethreitz/python-guide.git
synced 2026-06-05 14:50:19 +00:00
Cleaned up formatting and grammar
This commit is contained in:
@@ -597,7 +597,8 @@ Python will lose track of its current position.
|
||||
if i > 4:
|
||||
a.remove(i)
|
||||
|
||||
Python has standard ways of filtering lists, but there are several things you need to consider
|
||||
Python has a few standard ways of filtering lists.
|
||||
You will need to consider
|
||||
|
||||
* Python 2.x vs. 3.x
|
||||
* Lists vs. iterators
|
||||
@@ -606,19 +607,19 @@ Python has standard ways of filtering lists, but there are several things you ne
|
||||
Python 2.x vs. 3.x
|
||||
::::::::::::::::::
|
||||
|
||||
* Starting with Python 3.0, the :py:func:`map` and :py:func:`filter` functions return an iterator instead of a list. If you really need a list, you should wrap these functions in :py:func`list` like so
|
||||
Starting with Python 3.0, the :py:func:`filter` function returns an iterator instead of a list.
|
||||
If you really need a list, you should wrap it in :py:func:`list` like so
|
||||
|
||||
.. code-block:: python
|
||||
|
||||
list(map(...))
|
||||
list(filter(...))
|
||||
|
||||
* List comprehensions and generator expressions work the same in both 2.x and 3.x (except that comprehensions in 2.x "leak" variables into the enclosing namespace)
|
||||
List comprehensions and generator expressions work the same in both 2.x and 3.x (except that comprehensions in 2.x "leak" variables into the enclosing namespace)
|
||||
|
||||
* comprehensions create a new list object
|
||||
* generators iterate over the original list
|
||||
|
||||
* The filter function
|
||||
The :py:func:`filter` function
|
||||
|
||||
* in 2.x returns a list (use itertools.ifilter if you want an iterator)
|
||||
* in 3.x returns an iterator
|
||||
@@ -663,7 +664,7 @@ Modifying the values in a list
|
||||
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||||
**Bad**:
|
||||
|
||||
Remember that assignment never creates a new object. If 2 or more variables refer to the same list, changing one of them changes them all.
|
||||
Remember that assignment never creates a new object. If two or more variables refer to the same list, changing one of them changes them all.
|
||||
|
||||
.. code-block:: python
|
||||
|
||||
|
||||
Reference in New Issue
Block a user