Python self-study days--one Day notes-string concatenation + if while for loop

Comments
Single-line Comment #
Multiline comment ' three single quotation mark or three double quotation mark ""

"' use three quotation marks to enclose multiple lines of assignment

User interaction Input

string concatenation
+ "% ()" ". Format () Recommended use
Name = input ("Name:")
age = Int (input ("Age:"))
Sex = input ("Sex:")
Example: +
# string concatenation +
INFO1 = "----info in" + name + "'---
Name: "+ name +"
Age: "+ Age +"
Sex: "+ sex +"
‘‘‘
Example: ""% ()
#% formatted string
info = "'------info in%s-------
name:%s
age:%d
sex:%s
"% (" name "," name ", Age," sex ")

# "". Format ()
INFO3 = "---info in {_name}---
Name:{_name}
Age:{_age}
Sex:{_sex}
". Format (_name=name,
_age=age,
_sex=sex)
Info4 = "---info in {0}---
NAME:{0}
Age:{1}
SEX:{2} ". Format (name, age, Sex)

Module definition:
Ciphertext password: Getpass use after reference, Getpass.getpass ()
If Else uses
Cases:
Username = "username"
Password = "123456"
_username = Input ("Username:")
_PASSWD = Input ("Password:")
If username = = _username and Password = = _passwd:
Print ("Welcome user {Name} to Beij". Format (Name=username))
Else
Print ("Invalid username or passwd")

If elif Else
Cases:
Myage = 37
inputage = Int (input ("Please input my Age:"))
if inputage = = Myage:
Print ("It ' s Right")
Elif inputage > Myage:
Print ("Think small")
Else
Print ("Think big")

While else loop
Count = 0
While Count < 3:
Myage = 37
inputage = Int (input ("Please input my Age:"))
if inputage = = Myage:
Print ("It ' s Right")
Break
Elif inputage > Myage:
Print ("Think small")
Else
Print ("Think big")
Count+=1
Else
Print ("Fuck you!")

Break jumps out of the current entire loop
Continue jump out of the current loop and into the next loop

Homework

Writing the Login interface

• Enter User name password
• Show welcome message after successful authentication
• Three-time error after locking

Old_uname =OpenR ' C:\Users\Administrator\Desktop\username.txt ',' R '). ReadLines ()
Count =0
While Count <3:
Username =Input"Please your username:")
passwd =Input"Please your passwd:")
 For IIn Old_uname:
 If i = = Username:
 Print"Wolcome to your Blogs:{_uname}". Format (_uneme=username))
 Break
Else
 Continue
Else
Count + =1
 if Count = =3:
 Continue
 print ( else: 
  " three errors, account locked  open (r" C:\Users\Administrator\Desktop\ Lockname.txt '   "a"). Write (username +  
 
 String Base 
 (1), Escape string               
 (2), raw string--escape mechanism   open (R ' C:\tmp\a.txt ', ' A + ') 
 (3), Unicode string 
 (4), formatted string   "age%d,sex%s,record%" M.nf "% (," man ", 73.45) 
 String base operation 
  + connection, * Repeat, S[i] Index (index), s[i:j] slice (slice), for loop traversal 
   

Python self-taught days--one Day notes-string concatenation + if while for loop