## abs()
返回數字絕對值

```python
>>> abs(-100)
100
>>> abs(10)
10
>>>
```
## all()
判斷給定的可迭代引數 iterable 中的所有元素是否都為 TRUE，如果是返回 True，否則返回 False
```python
>>> all([100,100,100])
True
>>> all([3,0,1,1])
False
>>> 
```
## any()
判斷給定的可迭代引數 iterable 是否全部為 False，則返回 False，如果有一個為 True，則返回 True
```python
>>> any([0,0,0,0])
False
>>> any([0,0,0,1])
True
>>> 
```
## ascii()
呼叫物件的repr()方法，獲取該方法的返回值
```python
>>> ascii('test')
"'test'"
>>> 
```
## bin()
將十進位制轉換為二進位制
```python
>>> bin(100)
'0b1100100'
>>> 
```
## oct()
將十進位制轉換為八進位制
```python
>>> oct(100)
'0o144'
>>> 
```
## hex()
將十進位制轉換為十六進位制
```python
>>> hex(100)
'0x64'
>>> 
```
## bool()
測試物件是True，還是False
```python
>>> bool(1)
True
>>> bool(-1)
True
>>> bool()
False
>>> 
```
## bytes()
將一個字元轉換為位元組型別
```python
>>> s = "blxt"
>>> bytes(s,encoding='utf-8')
b'blxt'
>>> 
```
## str()
將字元、數值型別轉換為字串型別

```python
>>> str(123)
'123'
>>>
```
## callable()
檢查一個物件是否是可呼叫的

```python
False
>>> callable(str)
True
>>> callable(int)
True
>>> callable(0)
False
>>> 
```
## chr()
檢視十進位制整數對應的ASCll字元

```python
>>> chr(100)
'd'
>>> 
```
## ord()
檢視某個ascii對應的十進位制

```python

>>> ord('a')
97
>>> 
```
## classmethod()
修飾符對應的函式不需要例項化，不需要 self 引數，但第一個引數需要是表示自身類的 cls 引數，可以來呼叫類的屬性，類的方法，例項化物件等
```
#!/usr/bin/python
# -*- coding: UTF-8 -*-
 
class A(object):
    bar = 1
    def func1(self):  
        print ('foo') 
    @classmethod
    def func2(cls):
        print ('func2')
        print (cls.bar)
        cls().func1()   # 呼叫 foo 方法
 
```
輸出結果：
```
func2
1
foo
```
## compile()
將字串編譯成python能識別或者可以執行的程式碼。也可以將文字讀成字串再編譯

```python
>>> blxt = "print('hello')"
>>> test = compile(blxt,'','exec')
>>> test
<code object="" class=" prettyprint"> at 0x02E9B840, file "", line 1>
>>> exec(test)
hello
>>> 
```
## complex()
建立一個複數

```python
>>> complex(13,18)
(13+18j)
>>> 
```
## delattr()
刪除物件屬性

```
#!/usr/bin/python
# -*- coding: UTF-8 -*-
 
class Coordinate:
    x = 10
    y = -5
    z = 0
 
point1 = Coordinate() 
 
print('x = ',point1.x)
print('y = ',point1.y)
print('z = ',point1.z)
 
delattr(Coordinate, 'z')
 
print('--刪除 z 屬性後--')
print('x = ',point1.x)
print('y = ',point1.y)
 
# 觸發錯誤
print('z = ',point1.z)
```
輸出結果：

```python
>>> 
x =  10
y =  -5
z =  0
--刪除 z 屬性後--
x =  10
y =  -5
Traceback (most recent call last):
  File "C:\Users\fdgh\Desktop\test.py", line 22, in <module>
    print('z = ',point1.z)
AttributeError: 'Coordinate' object has no attribute 'z'
>>> 
```
## dict()
建立資料字典

```python
>>> dict()
{}
>>> dict(a=1,b=2)
{'a': 1, 'b': 2}
>>> 
```
## dir()
函式不帶引數時，返回當前範圍內的變數、方法和定義的型別列表
```python
>>> dir()
['Coordinate', '__annotations__', '__builtins__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__', 'point1', 'y']
>>> 
```
## divmod()
分別取商和餘數

```python
>>> divmod(11,2)
(5, 1)
>>> 
```
## enumerate()
返回一個可以列舉的物件，該物件的next()方法將返回一個元組

```python
>>> blxt = ['a','b','c','d']
>>> list(enumerate(blxt))
[(0, 'a'), (1, 'b'), (2, 'c'), (3, 'd')]
>>> 
```
## eval()
將字串str當成有效表示式來求值並返回計算結果取出字串中內容

```python
>>> blxt = "5+1+2"
>>> eval(blxt)
8
>>> 
```
## exec()
執行字串或complie方法編譯過的字串，沒有返回值
```python
>>> blxt = "print('hello')"
>>> test = compile(blxt,'','exec')
>>> test
<code object="" class=" prettyprint"> at 0x02E9B840, file "", line 1>
>>> exec(test)
hello
>>> 
```
## filter()
過濾器，構建一個序列

```python
#過濾列表中所有奇數
#!/usr/bin/python
# -*- coding: UTF-8 -*-
 
def is_odd(n):
    return n % 2 == 1
 
newlist = filter(is_odd, [1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
print(newlist)
```
輸出結果：
```python
[ 1, 3, 5, 7, 9 ]
```
## float()
將一個字串或整數轉換為浮點數
```python
>>> float(3)
3.0
>>> float(10)
10.0
>>> 
```
## format()
格式化輸出字串
```python	
>>> "{0} {1} {3} {2}".format("a","b","c","d")
'a b d c'
>>> print("網站名：{name},地址：{url}".format(name="blxt",url="www.blxt.best"))
網站名：blxt,地址：www.blxt.best
>>>
```
## frozenset()
建立一個不可修改的集合

```python
>>> frozenset([2,4,6,6,7,7,8,9,0])
frozenset({0, 2, 4, 6, 7, 8, 9})
>>> 
```
## getattr()
獲取物件屬性

```python
>>>class A(object):
...     bar = 1
... 
>>> a = A()
>>> getattr(a, 'bar')        # 獲取屬性 bar 值
1
>>> getattr(a, 'bar2')       # 屬性 bar2 不存在，觸發異常
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'A' object has no attribute 'bar2'
>>> getattr(a, 'bar2', 3)    # 屬性 bar2 不存在，但設定了預設值
3
>>>
```
## globals()
返回一個描述當前全域性變數的字典

```python
>>> print(globals()) # globals 函式返回一個全域性變數的字典，包括所有匯入的變數。
{'__builtins__': <module>, '__name__': '__main__', '__doc__': None, 'a': 'runoob', '__package__': None}
```
## hasattr()
函式用於判斷物件是否包含對應的屬性

```python
>>>class A(object):
...     bar = 1
... 
>>> a = A()
>>> hasattr(a,'bar')
True
>>> hasattr(a,'test')
False
```
## hash()
返回物件的雜湊值

```python
>>>class A(object):
...     bar = 1
... 
>>> a = A()
>>> hash(a)
-2143982521
>>> 
```
## help()
返回物件的幫助文件

```python
>>>class A(object):
...     bar = 1
... 
>>> a = A()
>>> help(a)
Help on A in module __main__ object:

>>> 
```
## id()
返回物件的記憶體地址
```python
>>>class A(object):
...     bar = 1
... 
>>> a = A()
>>> id(a)
56018040
>>> 
```
## input()
獲取使用者輸入內容

```python
>>> input()
... test
'test'
>>> 
```
## int()
用於將一個字串或數字轉換為整型

```python
>>> int('14',16)
20
>>> int('14',8)
12
>>> int('14',10)
14
>>>
```
## isinstance()
來判斷一個物件是否是一個已知的型別，類似 type()

```python
>>> test = 100
>>> isinstance(test,int)
True
>>> isinstance(test,str)
False
>>> 
```
## issubclass()	
用於判斷引數 class 是否是型別引數 classinfo 的子類

```php

#!/usr/bin/python
# -*- coding: UTF-8 -*-
 
class A:
    pass
class B(A):
    pass
    
print(issubclass(B,A))    # 返回 True

```
## iter()
返回一個可迭代物件，sentinel可省略

```python
>>>lst = [1, 2, 3]
>>> for i in iter(lst):
...     print(i)
... 
1
2
3
```
## len()
返回物件的長度

```python
>>> dic = {'a':100,'b':200}
>>> len(dic)
2
>>> 
```
## list()
返回可變序列型別

```python
>>> a = (123,'xyz','zara','abc')
>>> list(a)
[123, 'xyz', 'zara', 'abc']
>>> 
```
## map()
返回一個將function應用於iterable中每一項並輸出其結果的迭代器

```python
>>>def square(x) :            # 計算平方數
...     return x ** 2
... 
>>> map(square, [1,2,3,4,5])   # 計算列表各個元素的平方
[1, 4, 9, 16, 25]
>>> map(lambda x: x ** 2, [1, 2, 3, 4, 5])  # 使用 lambda 匿名函式
[1, 4, 9, 16, 25]
 
# 提供了兩個列表，對相同位置的列表資料進行相加
>>> map(lambda x, y: x + y, [1, 3, 5, 7, 9], [2, 4, 6, 8, 10])
[3, 7, 11, 15, 19]
```
## max()
返回最大值

```python
>>> max (1,2,3,4,5,6,7,8,9)
9
>>> 
```
## min()
返回最小值

```python
>>> min (1,2,3,4,5,6,7,8)
1
>>> 
```
## memoryview()	
返回給定引數的記憶體檢視物件(memory view)

```python
>>>v = memoryview(bytearray("abcefg", 'utf-8'))
>>> print(v[1])
98
>>> print(v[-1])
103
>>> print(v[1:4])
<memory at="">
>>> print(v[1:4].tobytes())
b'bce'
>>>
```
## next()
返回可迭代物件的下一個元素

```python
>>> a = iter([1,2,3,4,5])
>>> next(a)
1
>>> next(a)
2
>>> next(a)
3
>>> next(a)
4
>>> next(a)
5
>>> next(a)
Traceback (most recent call last):
  File "<pyshell>", line 1, in <module>
    next(a)
StopIteration
>>>
```
## object()
返回一個沒有特徵的新物件

```python
>>> a = object()
>>> type(a)
<class>
>>> 
```
## open()
返回檔案物件

```python
>>>f = open('test.txt')
>>> f.read()
'123/123/123'
```
## pow()
base為底的exp次冪，如果mod給出，取餘

```python
>>> pow (3,1,4)
3
>>> 
```
## print()
列印物件
## class property()
返回property屬性

```python
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.")
```
## range()
生成一個不可變序列

```python
>>> range(10)
range(0, 10)
>>> 
```
## reversed()
返回一個反向的iterator

```python
>>> a = 'test'
>>> a
'test'
>>> print(list(reversed(a)))
['t', 's', 'e', 't']
>>> 
```
## round（）
四捨五入

```python
>>> round (3.33333333,1)
3.3
>>> 
```
## class set()
返回一個set物件，可實現去重

```python
>>> a = [1,2,3,4,5,5,6,5,4,3,2]
>>> set(a)
{1, 2, 3, 4, 5, 6}
>>> 
```
## class slice()
返回一個表示有1range所指定的索引集的slice物件

```python
>>> a = [1,2,3,4,5,5,6,5,4,3,2]
>>> a[slice(0,3,1)]
[1, 2, 3]
>>> 
```
## sorted()
對所有可迭代的物件進行排序操作

```python
>>> a = [1,2,3,4,5,5,6,5,4,3,2]
>>> sorted(a,reverse=True)
[6, 5, 5, 5, 4, 4, 3, 3, 2, 2, 1]
>>> 
```
## @staticmethod
將方法轉換為靜態方法

```python
#!/usr/bin/python
# -*- coding: UTF-8 -*-
 
class C(object):
    @staticmethod
    def f():
        print('blxt');
 
C.f();          # 靜態方法無需例項化
cobj = C()
cobj.f()        # 也可以例項化後呼叫
```
輸出結果：
```python
	test
	test
```
## sum()
求和

```python
a = [1,2,3,4,5,5,6,5,4,3,2]
>>> sum(a)
40
>>> 
```
## super()
返回一個代理物件

```python
class A:
     def add(self, x):
         y = x+1
         print(y)
class B(A):
    def add(self, x):
        super().add(x)
b = B()
b.add(2)  # 3
```
## tuple()
不可變的序列型別

```python
>>> a = 'www'
>>> b =tuple(a)
>>> b
('w', 'w', 'w')
>>> 
```
## zip()
將可迭代的物件作為引數，將物件中對應的元素打包成一個個元組，然後返回由這些元組組成的列表

```python
>>>a = [1,2,3]
>>> b = [4,5,6]
>>> c = [4,5,6,7,8]
>>> zipped = zip(a,b)     # 打包為元組的列表
[(1, 4), (2, 5), (3, 6)]
>>> zip(a,c)              # 元素個數與最短的列表一致
[(1, 4), (2, 5), (3, 6)]
>>> zip(*zipped)          # 與 zip 相反，*zipped 可理解為解壓，返回二維矩陣式
[(1, 2, 3), (4, 5, 6)]
```
## [點選這裡跳轉個人部落格](https://www.blxt.best)</class></module></pyshell></memory></module></module></stdin></code></module></code>

Python內建函式示例

相關文章