python--regular expression, re module, Collections module, Random module, time module

Regular expressions
Meta-character quantifier (?)
Metacharacters:
.
\w \d \s \w \d \s
\ t \ \b
() |
[] [^]
^ $
Quantifiers:
* + ?
{n}, {n,}, {n,m}

Re module
How to invoke the RE module
Find: FindAll search match Finditer
Split and replace: Split Sub Subn
Compile: Compile Save time
How many places is the RE module used in?
Quantifier: Indicates a match 0 or 1 times
After the quantifier: is the sign of the lazy match
Group naming: (? p<name> Regular expression) when the reference (? P=name)
Findall/split Ungroup Priority: (?: Regular expression)
Collections Module
How to call the collections module
Namedtuple can name a tuple
Ordereddict ordered Dictionary
Defaultdict Default Dictionary
Deque Dual-ended queue
Counter counter
Queue queues
Advanced first-out features

RANDOMD module:
#随机小数 (Random,uniform), #随机整数 (Randent,randrange) #随机选择一个返回 (choice) #随机选择多个返回, the number returned is the second parameter of the function (sample)
#打乱列表顺序 (Shuffle)
Application scenario: On the phone, the page verification code
# 6-bit/4-digit number--Verification code
Import Random
s = '
For I in range (6):
num = str (random.randint (0,9))
s + = num
Print (s)

6-digit + letter-verification Code
CHR--Characters
res = '
For I in range (6):
num = str (random.randint (0, 9)) #数字
Al_num = Random.randint (97,122) #随机小写字母
al_num2 = Random.randint (65,90) Random capital letters
Alpha = Chr (al_num)
ALPHA2 = Chr (al_num2)
Res + = Random.choice ([NUM,ALPHA,ALPHA2])
Print (RES)
#生成随机验证码
Import Random
Def v_code ():
Code = "
For I in range (5):
Num=random.randint (0,9)
ALF=CHR (Random.randint (65,90))
Add=random.choice ([num,alf])
Code= "". Join ([Code,str (add)])
Return code
Print (V_code ())

#时间模块
Import Time #导入时间模块
#时间戳 (floating-point time):
Time.time ()
Print (Time.time ())
Print (Time.sleep (1))
#格式化时间 Time string
Time.strftime ("%y-%m-%d%x")

#格式化时间-----String for people to see.
Print (Time.strftime ('%h:%m:%s '))
Print (Time.strftime ('%y/%m/%d '))
Print (Time.strftime ('%y-%m-%d '))
Print (Time.strftime ('%c '))

Print (Time.strftime ('%c))

#结构化时间 (tuple)
Print (Time.locatime ())
# # (2018, 5, 22, 10, 36, 31, 1, 142, 0)

String time <--> structured time <---> timestamp time

Timestamps-transitions between structs
Print (Time.time ())
Print (Time.localtime (1500000000))
Print (Time.localtime (1600000000))
Print (Time.localtime (2000000000))
Print (Time.localtime (3000000000))
Print (Time.gmtime (3000000000))

Struct_time = Time.localtime (3000000000)
# Print (Time.mktime (struct_time))
ret = time.strftime ('%y/%m/%d%H :%m:%s ', struct_time)
Print (ret)
s_t = time.strptime (' 2028-5-21 ', '%y-%m-%d ')
Print (s_t)
Print ( Time.mktime (s_t))
#结构化时间 time stamp
#time. Mktime (structured time)
Time.mktime (time_tuple)
#结构化时间--string time
#time. strftime ("format definition", "structured Time") if the structured time parameter does not pass, the actual current time
Time.strftime ("%y-%m-%d%x"

#字符串时间-to-structured time
#time. Strptime (Time string, string corresponding format
Time.strptime ("2017-03-16", "%y-%m-%d")
Time difference calculation:
1. Convert to a floating-point timestamp 2. Two timestamp subtraction, 3. In turn back
Import time
True_time=time.mktime (Time.strptime (' 2017-09-11 08:30:00 ', '%y-%m-%d%h:%m:%s '))
Time_now=time.mktime (Time.strptime (' 2017-09-12 11:00:00 ', '%y-%m-%d%h:%m:%s '))
Dif_time=time_now-true_time
Struct_time=time.gmtime (Dif_time)
Print ('%d '%d '%d '%d '%d '% (struct_time.tm_year-1970,struct_time.tm_mon-1,
Struct_time.tm_mday-1,struct_time.tm_hour,
STRUCT_TIME.TM_MIN,STRUCT_TIME.TM_SEC))

python--regular expression, re module, Collections module, Random module, time module