Python expressions and operators and operation Precedence

Expressions and statements for Python:

Expression: A sequence of one or more operands and 0 or more operators.

Statement: The operation to be implemented.

Declare variables, assignment statements, control statements, conditional statements .... The order in which statements are executed in a program is called a control flow. is a single line of code ending with a semicolon, or a series of single-line statements in a statement block.

Expression operators commonly used in Python:

x + y, xy

× * y, x/y, x//y, x%y

x or y, x and Y, not X

X in Y, x not in Y

X is y, x isn't is Y

x < Y, x > Y, x<=y, x>=y,x = = y, x! = y

Bit operations:

x | Y, X & y, x ^y (XOR), x << y, x >> y

Unary operations:

-X, +x, ~x

Power Operation:

X * * y

Indexes and Shards:

Call Operation:

X (..... ）

Attribute operations:

X. Attribute

Tuples: (... ）

Sequence: [... ］

Dictionary: {... ｝

Ternary selection expression:

X if y else Z

Anonymous functions:

Lambda Args:expression generating an anonymous function expression

Generator function Send protocol:

Yield x

Operation Priority:

(),[],{}

S[I],S[I:J]

S.attribute

S (...)

+x,-X, ~x

X * * y

*,/,//,%

+, -

<<, >>

&

^

|

<=,< >,>= ==,!=

IS, isn't

In, not in

Not

and

Or

Lambda

The statements in Python:

Assignment statement;

Call

Print: Printing objects

If, elif, else,

For/else sequence iterations

While/else Normal Cycle

Pass: Placeholder

Break

Continue

Def:

Return

Yield

Global: namespaces

Raise: Triggering an exception

Import

From: Module Property access

Class: Classes

Try/except/finally: Catching exceptions

Del: Delete Reference

Assert: Debug Check

With/as: Environment Manager

Assignment statement: Variable names must be assigned in advance. Stealth assignment scenarios, import,from,def,class,for, function parameters

Tuples and lists: Supports decomposition assignment worth = left is a tuple or list, Python will match the right object and the left target according to the location, and the number will be different when it starts the exception, which can be done by slicing.

Multiple target assignment: NUM1 = num2 = num3 = 44

Enhanced Assignment: + =,-=,*=,/=,%=,//=

Python expressions and operators and operation Precedence