python[Little Turtle 008 Great branches and Loops 2]

Case: Rating the given score, the following are three options:

score = Int (input (' Please enter a fraction '))              #第一种方案if >= score >=:        print (' A ') if > score >=:        print (' B If > Score >=:        print (' C ') if 0 > Score >=:        print (' D ') Else:        print (' Input error! ‘)

　　

score = Int (input (' Please enter a fraction '))              #第二种方案if >= score >=:        print (' A ') Else:        if > Score >= 80:
   print (' B ')                else:                        if > Score >=:                                print (' C ')                        else: if-                                > Score >= 0:                                        Print (' D ')                                                else:                                                        print (' Input error! ‘)

　　

score = Int (input (' Please enter a fraction '))              #第三种方案if >= score >=:        print (' A ') elif > Score >=:        print ( ' B ') elif > Score >=: Print (        ' C ') elif > score >= 0:        print (' D ') Else:        print (' Input error! ‘)

　　

Of the above three scenarios, the third one has the lowest time complexity.

#注意 Hang Else

For example, a beginner in C can easily be fooled by a bit of code.

if (Hi > 2)    if (Hi > 7)        printf (' good ') Else    printf (' Fuck ')

　　

• Conditional expressions (Ternary operators)

syntax: x if condition else y

• Assertion (Assert)

Assert this keyword we call assertions, when the condition behind this keyword is false when the program automatically crashes, throwing Assertionerror exceptions.

As An example ,

Assert 3 > 4

　　

This statement is often used to set a checkpoint in a program, which is used to debug a program.

python[Little Turtle 008 Great branches and Loops 2]