Some ways to use Python numbers, strings, dictionaries, lists, Ganso, collections

Number: int integer effect: Age, grade, salary, ID card, QQ float float type effect: with decimal number

See self later when you don't see---------------------------------------------------

String: function: Name, gender, nationality, address, etc. description information

Definition: In quotation marks, double quotes, three quotation marks, consisting of a string of characters

Name= ' Elroy ' can only save one value

Common operations:

removing blank strip:

Name=input ("Username:")

Print (Name.strip ())

Effect: Username:eeee eeee

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Splitting split (cut into a list of lists):

user_info= ' Meng/xing/long/elroy ' Print (User_info.split ("/"))

Effect: [' Meng ', ' Xing ', ' long ', ' Elroy ']

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Length len:name= ' Elroy ' Print (len (name))

Effect: 5

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Index

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Slices (with a header without a tail in the specified range):

Name= ' Elroyy '

Print (Name[1:4])

Effect: LRO

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String Other methods:

Name= ' Elroy '

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Judge with what begins StartsWith:

Print (Name.startswith (' El '))

Effect: True

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Judge with what end EndsWith:

Print (Name.endswith (' Roy '))

Effect: True

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Replace Replace with string:

Name= ' Elroy Say:i has one tesla,my name is Elroy '

Print (Name.replace (' Elroy ', ' Heiheihei '))

Effect: Heiheihei say:i has one tesla,my name is Heiheihei

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String Increment format:

Three kinds: 1.print ("{}{}{}". Format (' Elroy ', ' ' ", ' IT ')

Effect: Elroy20it 2.print ("{0}{0}{1}". Format (' Elroy ', ' ' + ', ' IT ')

Effect: Elroyelroy20 *3.print ("{name}{age}{sex}". Format (name= ' Elroy ', sex= ' + ', age= ' IT '))

Effect: elroyIT20

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Determine if the input is a digital isdigit:

Age= ' 123123 '

Print (Age.isdigit ())

Effect: True

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Uppercase to lowercase:

Name= ' Elroy ' Print (Name.lower ())

Effect: Elroy

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Low-priority string handling:

Name= ' elroy123 '

Determines whether the isalnum consists of strings and numbers:

Print (Name.isalnum ())

Effect: True

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Determines whether the string consists of Isalpha:

Name= ' Elroy '

Print (Name.isalpha ())

Effect: True

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Digital judgment:

Num=b ' 3 ' #Bytes num1=u ' 3 ' #unicode

The default in Python3 is Unicode num2= ' four ' #中文数字 num3= ' IV ' #罗马数字

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Bytes,unicode can be judged by isdigit Unicode, Chinese numerals, Roman numerals can be isnumberic judged

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The list (which can be any data type) is ordered by string and list:

Common operations: Index slices

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* Additional append:

my_friends=[' Elroy ', ' Meng ', ' Xing ', ' Long '] my_friends.append (' Heiheihei ') print (my_friends)

Effect: [' Elroy ', ' Meng ', ' Xing ', ' long ', ' Heiheihei '-----------------------------------------------

* Append insert:

my_friends=[' Elroy ', ' Meng ', ' Xing ', ' Long '] my_friends.insert (2, ' Heiheihei ') print (my_friends)

Effect: [' Elroy ', ' Meng ', ' Heiheihei ', ' Xing ', ' long ']

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* Delete (delete by subscript) Pop:

my_friends=[' Elroy ', ' Meng ', ' Xing ', ' Long '] my_friends.append (' Heiheihei ') my_friends.pop (0)

Print (My_friends)

Effect: [' Meng ', ' Xing ', ' long ', ' Heiheihei ']

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* Delete (delete by string) Remove:

my_friends=[' Elroy ', ' Meng ', ' Xing ', ' Long '] print (my_friends) my_friends.remove (' Meng ')

Print (My_friends)

Effects: [' Elroy ', ' Meng ', ' Xing ', ' long '] [' Elroy ', ' Xing ', ' long ']

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* Length len:my_friends=[' Elroy ', ' Meng ', ' Xing ', ' long ']

Print (len (my_friends))

Effect: 4

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Cycle

Contains in

Other operations (Master) Clear clear:

my_friends=[' Elroy ', ' Meng ', ' Xing ', ' Long '] my_friends.clear ()

Print (My_friends) effect: []

Copy copy:my_friends=[' Elroy ', ' Meng ', ' Xing ', ' Long '] my_friends.clear ()

Print (My_friends) l=my_friends.copy () print (L)

Effect: [] []

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Counts the same string count:

my_friends=[' Elroy ', ' Meng ', ' Xing ', ' Long '] print (My_friends.count (' Long '))

Effect: 0

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Add all Extend:

My_friends.extend ([' Meng ', ' Xing ']) print (my_friends)

Effect: [' Meng ', ' Xing ']

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Reverse Reverse:

My_friends.reverse () print (my_friends)

Effect: [' long ', ' Xing ', ' Meng ', ' Elroy ']

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my_friends=[' Elroy ', ' Meng ', ' Xing ', ' long ']

Print (My_friends.index ("Elroy"))

Effect: 0---------------------------------------------

Tuples (immutable lists are generally used as read-only): Indes look at the subscript location, Count view the same number age= (11,22,33,44,55) View subscript index:print (Age.index (33)) 2 View a few 33count:print ( Age.count (33)) 1

The dictionary key must be an immutable type, also known as a hash type, unordered

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* Lift a value out of the dictionary pop:

info={' name ': ' Elroy ', ' age ':, ' sex ': ' SS '}

Print (Info.pop (' name '))

Effect: Elroy

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* Viewing from a dictionary the difference between a v,get,get and a normal value is that no value returns none:

Print (Info.get (' name '))

Effect: Elroy

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Unordered Bullets k/v Popitem:

info={' name ': ' Elroy ', ' age ':, ' sex ': ' SS '}

Print (Info.popitem ())

Effect: (' sex ', ' SS ')

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Play all k and V keys, values info={' name ': ' Elroy ', ' age ': +, ' sex ': ' SS '}

Print (Info.keys ()) print (Info.values ())

Effect: Dict_keys ([' Name ', ' age ', ' sex ']) dict_values ([' Elroy ', ' SS '])

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info={' name ': ' Elroy ', ' age ': +, ' sex ': ' SS '} for Key,value in Info.items ():

Print (Key,value) Effect: Name Elroy Age-Sex SS

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Clear clear:

info={' name ': ' Elroy ', ' age ':, ' sex ': ' SS '} info.clear ()

Print (info)

Effect: {}

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info={' name ': ' Elroy ', ' age ': +, ' sex ': ' SS '} dic=info.fromkeys ([' Name ', ' age ', ' sex '],22222)

Print (DIC)

Effect: {' name ': 22222, ' age ': 22222, ' Sex ': 22222}

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Goods = [{"Name": "Computer", "Price": 1999}, {"name": "Mouse", "Price": ten}, {"name": "Yacht", "Price": $}, {"Name" : "Beauty", "Price": 998},] Goods[0].setdefault (' AA ', []). Append (' one ') print (goods) effect: [{' name ': ' Computer ', ' Price ': 1999, ' AA ': [ ' One '}, {' name ': ' Mouse ', ' Price ': ten}, {' name ': ' Yacht ', ' Price ': $}, {' name ': ' Beauty ', ' Price ': 998}]

Set: Set de-weight and do relational operations set unordered: de-weight, relational operations (immutable types) (there can be multiple elements within a set, but each element must be immutable, i.e. not hash)

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De-weight: Elements within the collection unique S={1, ' a ', 1,1,1,1,1,1}

Print (s) Effect: {1, ' a '}

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Relational operations: s1={1,2,3,4} s2={3,4,5,6} intersection: Print (S1 & S2) {3,4} set: print (S1 | s2) Difference: print (S1-S2) print (S2-S1) symmetric difference set: Print (s1 ^ s2)

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Unimportant: s1={1,2,3,4} s2={1,2} parent set: print (S1 >= s2) Subset: print (S1 <= S2)

Some ways to use Python numbers, strings, dictionaries, lists, Ganso, collections