bool()：判斷真假

In [51]: bool(None) #None為假
Out[51]: False

In [52]: bool()     #空為假
Out[52]: False

In [53]: bool([])
Out[53]: False

In [55]: bool(())     #空列表，空元組都為假
Out[55]: False

In [58]: bool(0)     #1是真，0是假
Out[58]: False

In [59]: bool(1)
Out[59]: True

all()：都為真，才為真。否則就為假

In [49]: all([1,2])
Out[49]: True

In [50]: all([1,0])
Out[50]: False

In [61]: all(‘inter0‘)  #字符串是真的
Out[61]: True

any()：只要有1個為真，就為真

bin()：轉換成二進制

In [68]: bin(2)
Out[68]: ‘0b10‘

In [69]: bin(22)
Out[69]: ‘0b10110‘

random模塊 生成隨機數

In [70]: import random

In [71]: random.random()
Out[71]: 0.31270530531536544

In [72]: random.random()
Out[72]: 0.9740460087518201

In [76]: random.randint(1,100)    #生成範圍之內的數字
Out[76]: 69

enumerate()

In [78]: l = [‘x‘,‘y‘,‘z‘]

In [80]: el = enumerate(l)

In [83]: for i in el:
    ...:     print(i)
    ...:     
(0, ‘x‘)
(1, ‘y‘)
(2, ‘z‘)

In [84]: for i in enumerate(l,1):
    ...:     
    ...:     print(i)
    ...:     
(1, ‘x‘)
(2, ‘y‘)
(3, ‘z‘)

In [85]: for i,item in enumerate(l,1):
    ...:     
    ...:     print(i,item)
    ...:     
    ...:     
1 x
2 y
3 z

map()

接收2個參數，前面一個是函數名，後一個是列表（只能是列表？）

In [86]: l = [1,2,3,4,5]

In [87]: new_l = map(lambda x:x+100,l)

In [88]: new_l
Out[88]: <map at 0x7f456449af28>

In [89]: list(new_l)
Out[89]: [101, 102, 103, 104, 105]

filter()函數

In [92]: l
Out[92]: [1, 2, 3, 4, 5]

In [94]: def func(x):
    ...:     if x > 2:
    ...:         return True
    ...:     else:
    ...:         return False
    ...:     

In [95]: nw = filter(func,l)

In [96]: list(nw)
Out[96]: [3, 4, 5]

reversed() 反轉

round() 四舍五入

Python的內置函數