Python Basic data type

A data type

Numbers (shaping, long-shaped, floating-point, plural)

String

List

Meta-group

Dictionary

Collection

Two numbers (Int,float,complex)

Role: Age, grade, salary, Social security number, QQ number and other numbers related

Defined:

age=10 #本质age =int (10)

salary=3000.3 #本质salary =float (3000.3)

Binary, decimal, octal, hex

Long Plastic (Learn)

In Python2 (there is no concept of long shaping in Python3):

>>> num=2l
>>> type (num)
<type ' Long ' >

Plural (Learn)

>>> x=1-2j
>>> X.real
1.0
>>> X.imag
-2.0

Three strings

Role: Name, gender, nationality, address and other descriptive information

Definition: in single quotation marks \ double quotes \ Three quotation marks, consisting of a string of characters

Name= ' Egon '

Common operations:

removing blank Strip

Splitting split

Length Len

Index

Slice

Other operations (including common)

#strip Split---Split name='*egon**'Print (Name.strip ('*')) Print (Name.lstrip ('*')) Print (Name.rstrip ('*')) name='Root:x:0:0::/root:/bin/bash'Print (Name.split (':')) #默认分隔符为空格name='C:/a/b/c/d.txt'#只想拿到顶级目录print (Name.split ('/',1)) name='A|b|c'Print (Name.rsplit ('|',1)) #从右开始切分 # stitching: #jointag=' 'Print (Tag.join (['Egon','say','Hello',' World'])) #可迭代对象必须都是字符串 otherwise traverse #center,ljust,rjust,zfill,expandtabs Print related name='Egon'Print (Name.center ( -,'-')) Print (Name.ljust ( -,'*')) Print (Name.rjust ( -,'*')) Print (Name.zfill ( -)) #用0填充name='Egon\thello'print (name) print (Name.expandtabs (1)) #captalize, Swapcase,titleprint (Name.capitalize ()) #首字母大写print (Name.swapcase ()) #大小写翻转msg='Egon say hi'print (Msg.title ()) #每个单词的首字母大写 #replacename='Alex Say:i has one tesla,my name is Alex'Print (Name.replace ('Alex','SB',1)) #find, Rfind,index,rindex,count--Match Find name='Egon Say hello'Print (Name.find ('o',1,3)) #顾头不顾尾, if not found, returns-1 no error, found. Display index # print (Name.index ('e',2,4) #同上, but could not find the error print (Name.count ('e',1,3) #顾头不顾尾, find all test if you do not specify a range="12eioajflasfjoa"m= Str.maketrans ("AJF","456") print (Test.translate (m)) #format的三种玩法res='{} {} {}'. Format ('Egon', -,'male') Res='{1} {0} {1}'. Format ('Egon', -,'male') Res='{name} {age} {sex}'. Format (sex='male', name='Egon', age= -) #is其他print ('===>') name='egon123'print (Name.isalnum ()) #字符串由字母和数字组成print (Name.isalpha ()) #字符串只由字母组成print (Name.isidentifier ()) Print ( Name.islower ()) Print (Name.isupper ( )) print (Name.isspace ()) print (Name.istitle ())

Four list

Features: modifiable, memory does not need to be re-opened, can iterate

#Delete Way delList = ['1','5','2','3','4']delList[0]list.sort (Reverse=true)#DescendingList.remove ('2')#list.clear ()Print(list) Li= [A]list.append (LI)#[[1, 2, 3]]List.extend ([1,23])#[' 5 ', ' 4 ', ' 3 ', [1, 2, 3], 1, [+]Li.count (5) Li.insert (9,5) Li.insert (8,9)#the input position is out of bounds and will not be error #[' 5 ', ' 4 ', ' 3 ', [1, 2, 3, 5, 9], 1, at 1 [1, 2, 3, 5 , 9]Print(List,li.count (1), Li)

Five Yuan zu

Features: Can not be modified to add or remove the iteration list and Ganso can be converted to each other, the string can be Cheng Yuanju (after iteration), the meta-ancestor converted to a string (join or for)

Common operations:

Index

Slice

Cycle

Length

Contains in

Six dictionaries

A disorder (so the element cannot be found by slicing)

1, the value of the dictionary can be arbitrary

2. List cannot be used as key

3. Delete method: Del Dic[key], Dic.pop (key) D.clear ()

4, repeat can only keep one

5. Define the dictionary:

1) Dict.fromkeys (["K1,123," 999 "],123)

2) Dic.get (key) #不存在 None exists then returns the value corresponding to this key

3) dic.update (DIC1) #将字典 x all key-value pairs are added to dictionary D (not duplicated, duplicate key-value pairs are substituted in dictionary d for key-value pairs in dictionary x)

Python Basic data type