Python string concatenation + if while for loop example

Comments

Single-line Comment #

Multiline comment "' three single quotes or three double quotes" "

"Use three quotes to assign a multiple line

User interaction Input

string concatenation

+ ""% () "". Format () recommended

Name = input ("Name:")

age = Int (input (' Age: '))

Sex = input ("Sex:")

Example: +

# string concatenation +

INFO1 = '----info in ' + name + '---

Name: ' + name + '

Age: "+ Age +" "

Sex: ' + sex + '

'''

Example: ""% ()

#% format 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: Use after Getpass 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 Me Age:")

if inputage = = Myage:

Print ("It ' s Right")

Elif inputage > Myage:

Print ("small")

Else

Print ("Big")

While else loop

Count = 0

While Count < 3:

Myage = 37

inputage = Int (input ("Please input Me Age:")

if inputage = = Myage:

Print ("It ' s Right")

Break

Elif inputage > Myage:

Print ("small")

Else

Print ("Big")

Count+=1

Else

Print ("Fuck you!")

Break jumps out of the current loop

Continue out of the current loop and into the next loop

Homework

Write Login interface

Enter User name password
Show welcome information after successful authentication
Wrong three times, lock up.
Old_uname = open (R ' C:\Users\Administrator\Desktop\username.txt ', ' R '). ReadLines ()
Count = 0
While Count < 3:
Username = input ("Please your Username:")
passwd = input ("Please your passwd:")
For I in 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 ("The password you entered are incorrect!please input again ...")
Else
Print ("Three errors, account locked")
Open (R ' C:\Users\Administrator\Desktop\lockname.txt ', ' a '). Write (username + ' \ n ')

The

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 action
 + Connection, * Duplicate, S[i] Index (index), s[i:j] slice (slice), for loop traversal