Benefits: easy to understand

Disadvantages: Seems verbose, expression is not intuitive and clear enough

Benefits: Intuitive, clear

Disadvantages: It is large and difficult to modify

Benefit: Easier to be converted into programming language

A top-down structure that executes each step in the algorithm sequentially.

Also called a selection structure, it is a structure that makes judgments based on given conditions and then performs different operations based on the judgment results.

Note: The judgment box: one in and two out. The entire branch structure: one in and one out.

The loop structure is also called a repeating structure, which is a structure that repeatedly performs a certain part of the operation based on conditions. This part of the operation that is performed repeatedly is also called the loop body.

Current loop: first determine the condition, then execute the loop body. The loop body may not be executed even once

Until loop: execute the loop first, then judge the condition The loop body is executed at least once

Machine language is a set of machine instructions identified by binary code that can be directly recognized and executed by the computer.

An instruction is a statement in machine language

Benefits: Ability to directly identify and execute Disadvantages: Poor readability and compatibility

Replace the opcodes of machine instructions with something like English abbreviations Use address symbols or labels to replace the addresses of instructions or operands, and then convert them into machine language at runtime

Benefits: Highly readable, fast Disadvantages: Cannot be executed directly, poor compatibility

Based on daily human language, expressed in words that are easy for ordinary people to accept

Benefits: easy to write, high readability, does not depend on the hardware system

Identifier: int

Identifier: float

Identifier: str

Identifier: bool

It is directly given and refers to a quantity that does not change during the running of the program.

Refers to the amount that can be changed while the program is running.

The assignment symbol in "for Python" is to change the right side of the assignment number The evaluation result of the expression is stored in the variable specified to the left of the assignment number.

Addition, operator " ", priority "3"

Subtraction, operator "-", priority "3"

Multiplication, operator "*", priority "2"

Division, operator "/", priority "2"

Remainder, operator "%", priority "2"

Power, operator "**", priority "1"

Integer division, operator "//", priority "2"

Equal to, operator "==", for example (a=10, b=20) a==b, returns false

Greater than, operator ">", a>b, returns false

Less than, operator "<", a<b, returns true

Greater than or equal to, operator ">="a>=b, returns false

Less than or equal to, operator "<=", a<=b, returns true

Not equal to, operator "!=", a!=b, returns true

Not, operator "not", priority "1", not (a==b), if a and b are equal, return false, otherwise return true

And, operator "and", priority "2", a and b, the result is true only when a and b are both true.

Or, operator "or", priority "3", a or b, as long as either a or b is true, the result is true

Basic format: if conditional expression: statement block

if conditional expression: Statement block 1 else: Statement block 2

if conditional expression 1: Statement block 1 elif conditional expression 2: Statement block 2 … else: Statement block n

while conditional expression: statement block

for loop variable in sequence: statement block

range (1, 5, 3), description: Generate a sequence with a starting value of 1, a final value of 4, and a step size of 3: [1, 4]

range (1, 5), description: Generate a sequence with a starting value of 1, a final value of 4, and a default step value of 1: [1, 2, 3, 4]

range(5), description: Generate a sequence with a starting value of 0 (no starting value is set, the default is 0), a final value of 4, and a step size of 1: [0, 1, 2, 3, 4 】

range (5, 1, -1), description; generate a sequence with a starting value of 5, a final value of 2, and a step size of 1: [5, 4, 3, 2]