Here's a generator that yields the chunks you want:
def chunks(lst, n):
"""Yield successive n-sized chunks from lst."""
for i in range(0, len(lst), n):
yield lst[i:i + n]
import pprint
pprint.pprint(list(chunks(range(10, 75), 10)))
[[10, 11, 12, 13, 14, 15, 16, 17, 18, 19],
[20, 21, 22, 23, 24, 25, 26, 27, 28, 29],
[30, 31, 32, 33, 34, 35, 36, 37, 38, 39],
[40, 41, 42, 43, 44, 45, 46, 47, 48, 49],
[50, 51, 52, 53, 54, 55, 56, 57, 58, 59],
[60, 61, 62, 63, 64, 65, 66, 67, 68, 69],
[70, 71, 72, 73, 74]]
If you're using Python 2, you should use xrange()
instead of range()
:
def chunks(lst, n):
"""Yield successive n-sized chunks from lst."""
for i in xrange(0, len(lst), n):
yield lst[i:i + n]
Also you can simply use list comprehension instead of writing a function, though it's a good idea to encapsulate operations like this in named functions so that your code is easier to understand. Python 3:
[lst[i:i + n] for i in range(0, len(lst), n)]
Python 2 version:
[lst[i:i + n] for i in xrange(0, len(lst), n)]
In this code:
class A(object):
def __init__(self):
self.x = 'Hello'
def method_a(self, foo):
print self.x + ' ' + foo
... the self
variable represents the instance of the object itself. Most object-oriented languages pass this as a hidden parameter to the methods defined on an object; Python does not. You have to declare it explicitly. When you create an instance of the A
class and call its methods, it will be passed automatically, as in ...
a = A() # We do not pass any argument to the __init__ method
a.method_a('Sailor!') # We only pass a single argument
The __init__
method is roughly what represents a constructor in Python. When you call A()
Python creates an object for you, and passes it as the first parameter to the __init__
method. Any additional parameters (e.g., A(24, 'Hello')
) will also get passed as arguments--in this case causing an exception to be raised, since the constructor isn't expecting them.
Best Answer
From What's New in Python 3.0
The function attributes named
func_X
have been renamed to use the__X__
form, freeing up these names in the function attribute namespace for user-defined attributes. To wit,func_closure
,func_code
,func_defaults
,func_dict
,func_doc
,func_globals
,func_name
were renamed to__closure__
,__code__
,__defaults__
,__dict__
,__doc__
,__globals__
,__name__
, respectively.Basically, same old Python 2 stuff, fancy new Python 3000 name.
You can learn more about most of these in PEP 232