"Python" conditional judgment and looping with Dict and set

# Conditional Judgment

The role of Elif:else if

Note: "Colon"
BMI =w/(h*h)

If bmi<15:
Print (' lighter ')
Elif bmi<25:
Print (' normal ')
else BIM:
Print (' obese ')

# loops

For x in XS a bit like the C # foreach
Range () generates an integer sequence, range (101) generates an integer sequence of 0~100

While loop

Find different
One

n = one while n>10:    n-1    print(n)

Two

n = ten while n >:    = n-1    print('1', N)

The difference between one and two,,,

#dict和set

Dict Dictionary dictionary shorthand,

Key-value Storage,

Fast, indexed,

Advantages compared to list

1. The speed of finding and inserting is very fast and will not increase with the increase of key;
2. It takes a lot of memory, and it wastes a lot of memory.

Disadvantages:

1. The time to find and insert increases as the element increases;
2. Small footprint and little wasted memory.

Set and dict are immutable pairs of objects

Immutable objects--just change the value, the object itself does not change.

Where do you use it???

"Python" conditional judgment and looping with Dict and set