python基础--random包、string包

random随机包

>>> import random  #导入随机包
#取随机整数
>>> random.randint(1,10)
4
#取夸指定步长的随机整数
>>> random.randrange(1,10,2)  #随机取1-10之间的奇数
9
>>> random.randrange(0,10,2)
2

#去0-1之间的随机小数
>>> random.random()
0.25631948996842346

#取指定区间的随机小数
>>> random.uniform(1,10)
3.1196351125028334
>>> random.uniform(1,10)
5.857263369842762
>>>

#随机取一个字符
>>> random.choice(‘abcdefg‘)
‘f‘
#随机取指定个数字符
>>> random.sample(‘abcdefg‘,3)
[‘f‘, ‘d‘, ‘e‘]

#随机打乱排序，只能针对列表；原地乱序：改变原列表的顺序，且不返回值，返回的是None
>>> s=[1,2,3,4,5]
>>> random.shuffle(s)
>>> s
[3, 4, 1, 2, 5]



#生成随机的十个小写字母

>>> result =""
>>> for i in range(10):
...     result +=chr(97+random.randint(1,25))
...
>>> print(result)
iiixvsfltw

#生成随机不限定大小写个数的10个字母

>>> result=""
>>> lower_case_letter_num = random.randint(1,9)
>>> upper_case_letter_num = 10-lower_case_letter_num
>>> for i in range(lower_case_letter_num):
... result +=chr(ord("a")+random.randint(1,25))
...
>>> for i in range(upper_case_letter_num):
... result +=chr(ord("A")+random.randint(1,25))
...
>>> print(result)
ypskdkIDTN

string包

>>> import string  #导入string包 >>> dir(string)   #查看该包里有哪些方法
[‘Formatter‘, ‘Template‘, ‘_ChainMap‘, ‘_TemplateMetaclass‘, ‘__all__‘, ‘__built
ins__‘, ‘__cached__‘, ‘__doc__‘, ‘__file__‘, ‘__loader__‘, ‘__name__‘, ‘__packag
e__‘, ‘__spec__‘, ‘_re‘, ‘_string‘, ‘ascii_letters‘, ‘ascii_lowercase‘, ‘ascii_u
ppercase‘, ‘capwords‘, ‘digits‘, ‘hexdigits‘, ‘octdigits‘, ‘printable‘, ‘punctua
tion‘, ‘whitespace‘]
>>> string.ascii_letters   #获取所有的字母（包括大写和小写） ‘abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ‘
>>> string.ascii_lowercase   #获取所有小写字母 ‘abcdefghijklmnopqrstuvwxyz‘
>>> string.ascii_uppercase    #获取所有大写字母 ‘ABCDEFGHIJKLMNOPQRSTUVWXYZ‘
>>> string.digits   #获取所有数字 ‘0123456789‘

练习：

# 从a-zA-Z0-9生成指定数量的随机字符：
>>> string.ascii_letters
‘abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ‘
>>> string.digits
‘0123456789‘
>>> random.sample(string.ascii_letters+string.digits,8)
[‘n‘, ‘q‘, ‘f‘, ‘7‘, ‘L‘, ‘p‘, ‘I‘, ‘y‘]
>>> ‘‘.join(random.sample(string.ascii_letters+string.digits,8))
‘GgHXmqbj‘
>>> ‘‘.join(random.sample(string.ascii_letters+string.digits,8))
‘XFCf2KvQ‘