各位还是参考官方文档吧，我这些是自己感觉重要和常用的
abs
()
all
(iterable) 如果迭代序列中所有的元素都为真，或者迭代序列为空的时候返回
True
。等价于：
def
all
(iterable):
for
element
in
iterable:
if
not
element:
return
False
return
True
all
(iterable) 如果迭代序列中所有的元素都为真，返回
True
。等价于
def
any
(iterable):
for
element
in
iterable:
if
element:
return
True
return
False
complex
（）创建复数：
>>>
complex
(
1
,
2
)
(
1
+
2j
)
>>>
complex
(
1
)
(
1
+
0j
)
delattr
(
object
, name)
For example,
delattr
(x,
'foobar'
)
is
equivalent to
del
x.foobar.
dict
（）创建字典
dir
()
>>>
import
struct
>>>
dir
()
# show the names in the module namespace
[
'__builtins__'
,
'__doc__'
,
'__name__'
,
'struct'
]
>>>
dir
(struct)
# show the names in the struct module
[
'Struct'
,
'__builtins__'
,
'__doc__'
,
'__file__'
,
'__name__'
,
'__package__'
,
'_clearcache'
,
'calcsize'
,
'error'
,
'pack'
,
'pack_into'
,
'unpack'
,
'unpack_from'
]
>>>
class
Shape(
object
):
def
__dir__(
self
):
return
[
'area'
,
'perimeter'
,
'location'
]
>>> s
=
Shape()
>>>
dir
(s)
[
'area'
,
'perimeter'
,
'location'
]
divmod
(I,j)返回以商和余数组成的元祖：
>>>
divmod
(
10
,
3
)
(
3
,
1
)
enumerate
(sequence[, start
=
0
])
>>> seasons
=
[
'Spring'
,
'Summer'
,
'Fall'
,
'Winter'
]
>>>
list
(
enumerate
(seasons))
[(
0
,
'Spring'
), (
1
,
'Summer'
), (
2
,
'Fall'
), (
3
,
'Winter'
)]
>>>
list
(
enumerate
(seasons, start
=
1
))
[(
1
,
'Spring'
), (
2
,
'Summer'
), (
3
,
'Fall'
), (
4
,
'Winter'
)]
其实也就等价于：
def
enumerate
(sequence, start
=
0
):
n
=
start
for
elem
in
sequence:
yield
n, elem
n
+
=
1
eval
(expression[,
globals
[,
locals
]])
>>> x
=
1
>>>
print
eval
(
'x+1'
)
2
filter
(function, iterable)
is
equivalent to [item
for
item
in
iterable
if
function(item)]
if
function
is
not
None
and
[item foritem
in
iterable
if
item]
if
function
is
None
.
getattr
(
object
, name[, default])
For example,
getattr
(x,
'foobar'
)
is
equivalent to x.foobar.
hasattr
(
object
, name)
help
([
object
])¶
hex
(x) 将整形x转化为
16
进制字符串，如果想要转化浮点型，可以使用
float
.
hex
(x)
id
(
object
) 对象的内存地址
input
([prompt]) Equivalent to
eval
(
raw_input
(prompt)).
isinstance
(
object
, classinfo)
issubclass
(
class
, classinfo)
iter
(o[, sentinel]) 迭代o,直到指和sentinel相等。例如：reads a
file
until the readline() method returns an empty string:
with
open
(
'mydata.txt'
) as fp:
for
line
in
iter
(fp.readline, ''):
process_line(line)
map
(function, iterable, ...)
Apply
function to every item of iterable
and
return
a
list
of the results.
max
(iterable[, args...][, key])
min
(iterable[, args...][, key])
next
(iterator[, default])
oct
(x)
Convert an integer number (of
any
size) to an octal string. The result
is
a valid Python expression.
open
(name[, mode[, buffering]])
property
([fget[, fset[, fdel[, doc]]]])
class
C(
object
):
def
__init__(
self
):
self
._x
=
None
def
getx(
self
):
return
self
._x
def
setx(
self
, value):
self
._x
=
value
def
delx(
self
):
del
self
._x
x
=
property
(getx, setx, delx,
"I'm the 'x' property."
)
创建只读属性：这个属性的值就不能修改了
class
Parrot(
object
):
def
__init__(
self
):
self
._voltage
=
100000
@property
def
voltage(
self
):
"""Get the current voltage."""
return
self
._voltage
class
C(
object
):
def
__init__(
self
):
self
._x
=
None
@property
def
x(
self
):
"""I'm the 'x' property."""
return
self
._x
@x
.setter
def
x(
self
, value):
self
._x
=
value
@x
.deleter
def
x(
self
):
del
self
._x
range
([start], stop[, step])
>>>
range
(
10
)
[
0
,
1
,
2
,
3
,
4
,
5
,
6
,
7
,
8
,
9
]
>>>
range
(
1
,
11
)
[
1
,
2
,
3
,
4
,
5
,
6
,
7
,
8
,
9
,
10
]
>>>
range
(
0
,
30
,
5
)
[
0
,
5
,
10
,
15
,
20
,
25
]
>>>
range
(
0
,
10
,
3
)
[
0
,
3
,
6
,
9
]
>>>
range
(
0
,
-
10
,
-
1
)
[
0
,
-
1
,
-
2
,
-
3
,
-
4
,
-
5
,
-
6
,
-
7
,
-
8
,
-
9
]
>>>
range
(
0
)
[]
>>>
range
(
1
,
0
)
[]
reduce
(function, iterable[, initializer])
Apply
function of two arguments cumulatively to the items of iterable,
from
left to right, so as to
reduce
the iterable to a single value. For example,
reduce
(
lambda
x, y: x
+
y, [
1
,
2
,
3
,
4
,
5
]) calculates ((((
1
+
2
)
+
3
)
+
4
)
+
5
). The left argument, x,
is
the accumulated value
and
the right argument, y,
is
the update value
from
the iterable. If the optional initializer
is
present, it
is
placed before the items of the iterable
in
the calculation,
and
serves as a default when the iterable
is
empty. If initializer
is
not
given
and
iterable contains only one item, the first item
is
returned.
round
(x[, n])
>>>
round
(
1.12313
,
2
)
1.12
slice
([start], stop[, step])
sorted
(iterable[,
cmp
[, key[, reverse]]])
staticmethod
(function)
Return a static method
for
function.
class
C:
@staticmethod
def
f(arg1, arg2, ...): ...
sum
(iterable[, start])
tuple
([iterable])
>>>
tuple
(
"ada"
)
(
'a'
,
'd'
,
'a'
)
zip
([iterable, ...])
zip
()
in
conjunction with the
*
operator can be used to unzip a
list
:
>>> x
=
[
1
,
2
,
3
]
>>> y
=
[
4
,
5
,
6
]
>>> zipped
=
zip
(x, y)
>>> zipped
[(
1
,
4
), (
2
,
5
), (
3
,
6
)]
>>> x2, y2
=
zip
(
*
zipped)
>>> x
=
=
list
(x2)
and
y
=
=
list
(y2)
True
>>>
float
.fromhex(
'0x3.a7p10'
)
3740.0
>>> lists
=
[[]]
*
3
>>> lists
[[], [], []]
>>> lists[
0
].append(
3
)
>>> lists
[[
3
], [
3
], [
3
]]
>>> lists
=
[[]
for
i
in
range
(
3
)]
>>> lists[
0
].append(
3
)
>>> lists[
1
].append(
5
)
>>> lists[
2
].append(
7
)
>>> lists
[[
3
], [
5
], [
7
]]
>>>
"The sum of 1 + 2 is {0}"
.
format
(
1
+
2
)
'The sum of 1 + 2 is 3'
>>>
"they're bill's friends from the UK"
.title()
"They'Re Bill'S Friends From The Uk"
>>>
print
'%(language)s has %(number)03d quote types.'
%
\
... {
"language"
:
"Python"
,
"number"
:
2
}
Python has
002
quote types.
>>> dishes
=
{
'eggs'
:
2
,
'sausage'
:
1
,
'bacon'
:
1
,
'spam'
:
500
}
>>> keys
=
dishes.viewkeys()
>>> values
=
dishes.viewvalues()
>>>
# iteration
>>> n
=
0
>>>
for
val
in
values:
... n
+
=
val
>>>
print
(n)
504
>>>
# keys and values are iterated over in the same order
>>>
list
(keys)
[
'eggs'
,
'bacon'
,
'sausage'
,
'spam'
]
>>>
list
(values)
[
2
,
1
,
1
,
500
]
>>>
# view objects are dynamic and reflect dict changes
>>>
del
dishes[
'eggs'
]
>>>
del
dishes[
'sausage'
]
>>>
list
(keys)
[
'spam'
,
'bacon'
]
>>>
# set operations
>>> keys & {
'eggs'
,
'bacon'
,
'salad'
}
{
'bacon'
}
>>> v
=
memoryview(
'abcefg'
)
>>> v[
1
]
'b'
>>> v[
-
1
]
'g'
>>> v[
1
:
4
]
<memory at
0x77ab28
>
>>> v[
1
:
4
].tobytes()
'bce'
>>> data
=
bytearray(
'abcefg'
)
>>> v
=
memoryview(data)
>>> v.readonly
False
>>> v[
0
]
=
'z'
>>> data
bytearray(b
'zbcefg'
)
>>> v[
1
:
4
]
=
'123'
>>> data
bytearray(b
'z123fg'
)
>>> v[
2
]
=
'spam'
Traceback (most recent call last):
File
"<stdin>"
, line
1
,
in
<module>
ValueError: cannot modify size of memoryview
object
>>> m
=
memoryview(
"abc"
)
>>> m.tobytes()
'abc'
>>> memoryview(
"abc"
).tolist()
[
97
,
98
,
99
]
|
