python模块2 math\random\re\time\datetime模块

1 >>> import math
2 >>> dir(math)
3 [‘__doc__‘, ‘__loader__‘, ‘__name__‘, ‘__package__‘, ‘__spec__‘, ‘acos‘, ‘acosh‘, ‘asin‘, ‘asinh‘, ‘atan‘, ‘atan2‘, ‘atanh‘, ‘ceil‘, ‘copysign‘, ‘cos‘, ‘cosh‘, ‘degrees‘, ‘e‘, ‘erf‘, ‘erfc‘, ‘exp‘, ‘expm1‘, ‘fabs‘, ‘factorial‘, ‘floor‘, ‘fmod‘, ‘frexp‘, ‘fsum‘, ‘gamma‘, ‘gcd‘, ‘hypot‘, ‘inf‘, ‘isclose‘, ‘isfinite‘, ‘isinf‘, ‘isnan‘, ‘ldexp‘, ‘lgamma‘, ‘log‘, ‘log10‘, ‘log1p‘, ‘log2‘, ‘modf‘, ‘nan‘, ‘pi‘, ‘pow‘, ‘radians‘, ‘sin‘, ‘sinh‘, ‘sqrt‘, ‘tan‘, ‘tanh‘, ‘tau‘, ‘trunc‘]

1 e = 2.718281828459045
2 pi = 3.141592653589793

import math
print(math.pi)
print(math.e)

1 >>> import math
2 >>> math.log(100, 10)
3 2
4 >>> math.log(10, 100)
5 0.5
6 >>> math.log10(100)
7 2.0
8 >>> math.log10(1000)
9 3.0

 1 >>> import math
 2 >>> math.modf(5.23)
 3 (0.23000000000000043, 5.0)
 4 >>> math.modf(5.31)
 5 (0.3099999999999996, 5.0)
 6 >>> math.pow(2, 3)
 7 8.0
 8 >>> math.pow(2, 2)
 9 4.0
10 >>> math.sqrt(9)
11 3.0
12 >>> math.sqrt(4)
13 2.0

1 >>> import random
2 >>> dir(random)
3 [‘BPF‘, ‘LOG4‘, ‘NV_MAGICCONST‘, ‘RECIP_BPF‘, ‘Random‘, ‘SG_MAGICCONST‘, ‘SystemRandom‘, ‘TWOPI‘, ‘_BuiltinMethodType‘, ‘_MethodType‘, ‘_Sequence‘, ‘_Set‘, ‘__all__‘, ‘__builtins__‘, ‘__cached__‘, ‘__doc__‘, ‘__file__‘, ‘__loader__‘, ‘__name__‘, ‘__package__‘, ‘__spec__‘, ‘_acos‘, ‘_bisect‘, ‘_ceil‘, ‘_cos‘, ‘_e‘, ‘_exp‘, ‘_inst‘, ‘_itertools‘, ‘_log‘, ‘_pi‘, ‘_random‘, ‘_sha512‘, ‘_sin‘, ‘_sqrt‘, ‘_test‘, ‘_test_generator‘, ‘_urandom‘, ‘_warn‘, ‘betavariate‘, ‘choice‘, ‘choices‘, ‘expovariate‘, ‘gammavariate‘, ‘gauss‘, ‘getrandbits‘, ‘getstate‘, ‘lognormvariate‘, ‘normalvariate‘, ‘paretovariate‘, ‘randint‘, ‘random‘, ‘randrange‘, ‘sample‘, ‘seed‘, ‘setstate‘, ‘shuffle‘, ‘triangular‘, ‘uniform‘, ‘vonmisesvariate‘, ‘weibullvariate‘]

 1 import random
 2 # (0,1)----float    大于0且小于1之间的小数
 3 print(random.random())
 4 
 5 # [1,3]    大于等于1且小于等于3之间的整数
 6 print(random.randint(1, 3))
 7 
 8 # [1,3)    大于等于1且小于3之间的整数
 9 print(random.randrange(1, 3))
10 
11 # 1或者23或者[4,5]
12 print(random.choice([1, ‘23‘, [4, 5]]))
13 
14 # 列表元素任意2个组合
15 print(random.sample([1, ‘23‘, [4, 5]], 2))
16 
17 # 大于1小于3的小数，如1.927109612082716
18 print(random.uniform(1, 3))

 1 # 生成一个随机验证码: 前两位是英文字母，后三位是数字
 2 import random
 3 checkcode = ‘‘
 4 
 5 for i in range(5):
 6     current = random.randint(0, 5)
 7     # 字母
 8     if i == 0 or i == 1:
 9         tmp = chr(random.randint(65, 90))
10     # 数字
11     else:
12         tmp = random.randint(0, 9)
13     checkcode += str(tmp)
14 print(checkcode)

1 import string
2 import random
3 
4 # x中包含了所以的数字、大小写字母和符号
5 x = string.digits + string.ascii_letters + string.punctuation
6 
7 # random中的choice() -> 是从序列中任意选择一个元素
8 pwd = ‘‘.join([random.choice(x) for i in range(8)])
9 print(pwd)

 1 ‘.‘     默认匹配除\n之外的任意一个字符，若指定flag DOTALL,则匹配任意字符，包括换行
 2 ‘^‘     匹配字符开头，若指定flags MULTILINE,这种也可以匹配上(r"^a","\nabc\neee",flags=re.MULTILINE)
 3 ‘$‘     匹配字符结尾，或e.search("foo$","bfoo\nsdfsf",flags=re.MULTILINE).group()也可以
 4 ‘*‘     匹配*号前的字符0次或多次，re.findall("ab*","cabb3abcbbac")  结果为[‘abb‘, ‘ab‘, ‘a‘]
 5 ‘+‘     匹配前一个字符1次或多次，re.findall("ab+","ab+cd+abb+bba") 结果[‘ab‘, ‘abb‘]
 6 ‘?‘     匹配前一个字符1次或0次
 7 ‘{m}‘   匹配前一个字符m次
 8 ‘{n,m}‘ 匹配前一个字符n到m次，re.findall("ab{1,3}","abb abc abbcbbb") 结果‘abb‘, ‘ab‘, ‘abb‘]
 9 ‘|‘     匹配|左或|右的字符，re.search("abc|ABC","ABCBabcCD").group() 结果‘ABC‘
10 ‘(...)‘ 分组匹配，re.search("(abc){2}a(123|456)c", "abcabca456c").group() 结果 abcabca456c
11  
12  
13 ‘\A‘    只从字符开头匹配，re.search("\Aabc","alexabc") 是匹配不到的
14 ‘\Z‘    匹配字符结尾，同$
15 ‘\d‘    匹配数字0-9
16 ‘\D‘    匹配非数字
17 ‘\w‘    匹配[A-Za-z0-9]
18 ‘\W‘    匹配非[A-Za-z0-9]
19 ‘s‘     匹配空白字符、\t、\n、\r , re.search("\s+","ab\tc1\n3").group() 结果 ‘\t‘
20