Self-taught Python first time finishing

First, learn the history of Python and some nouns

Explanatory language: Side compilation Edge execution

Compiled language: first compiled and executed such as C,python

Dynamic languages: No need to declare variable types, Eg:python Ruby

Static language: Variable types need to be declared

Strongly typed languages: Once you define a type, you must undergo a forced conversion to become another type of Python

Weakly typed languages: Data types can be ignored

Second, the advantages of Python

Simple, efficient, high-level language, portability, extensibility, embeddable

Disadvantages:

Slow, non-encrypted, multi-threaded (Pypy,ps:pypy is Python's fastest IDE if you want the code to be fast)

Third, variable

Ageofoldboy =    #驼峰表示法 age_of_oldboy =  #一般的方法 age_of_oldboy =  #这个是代表着常量 Letters all uppercase nominally represent constants but are essentially variables

(1), variable cannot start with a number

(2), cannot be interspersed with special characters

(3), can not be the key in order to give the variable name

Four, character code

ASCLL (1B)--gb2312 (7,000 multi-kanji)-GBK (supports 2w+ kanji)-gb18030 (2.7w+ kanji)

Final to unified encoded Unicode (16-bit)

UTF8 English 1B Chinese 3B

(Python 2 needs to define UTF-8 characters and Python 3 doesn't need to define Chinese character encodings)

Five, the Code

• Comments
  Single-line Comment #代码
  Multi-line Comment ' code '
• %s placeholder

# . Formatname = input ("name  :") Age = Input ("Age: ")   # int (Input ("Age:"))Job  = input ("job:" " -------info of {na}---------Name: {na}age:  {ag}job:  '. Format (na=name,ag=age,jo=job)print(Info2)

1Name = input ("Name:")2Age = Input ("Age :")#int (Input ("Age:"))3Job = input ("Job:")4info =" "5 --------Info of%s-----6 name:%s7 age:%s8 job:%s9  " "%(name, name, age, Job)Ten Print(info)

• Import imports the standard library
• The individual code must be shelf written
• While if break (understand the purpose of the last else PS: when there is no execution result on the top while the else below is executed)

_username ="SGS"_password="121"Count=0 whileCount<3: Username= Input ("Username:") Password= Input ("Password:")    if_username==username and_password==Password:Print("Welcome you!")         Break    Else:        Print("Username or PASSWRD was error") Count+=1Else:    Print("User lock!")

• In parentheses (starting value, terminating value, step size)

 for  in range (0,10,2):    if i<3:        print(i)      else  :        continue    print("hehe")

• Understand the meaning of break and Continue: Break is the end of the current loop, Continue end this cycle into the next loop!

　　

Self-taught Python first time finishing