Small knowledge points in Python

Here is a collection of small knowledge points, for the convenience of later search.

Line and indent:

Physical line: The number of lines of code actually seen.

Logical line: function in meaning (that is, the number of rows performed by the interpreter)

If a physical row contains more than one logical row, each logical line needs to be separated by a semicolon ";" , and the last logical line can omit the semicolon

A logical line is divided into multiple physical lines using the escape character "\" to make a connection between each physical row

Indent: white space at the beginning of a logical line, usually without leaving a blank at the beginning

Indent for if and while statements: one tab character under conditions

Operator:

: Division, rounding down

%: Take the remainder

&: Bitwise AND operation in binary

|: Bitwise OR

^: Bitwise XOR (different 1, same as 0)

~: Bitwise rollover ~x=-(X+1)

<<: Binary left shift, left n units equal to multiplied by 2^n

>>: Binary right SHIFT, right shift n units equal to divided by 2^n

Operator Precedence:

1. 1. function invocation, addressing, subscript
   2. Power Operation * *
   3. Rollover operations
   4. PLUS sign
   5. *  /   %
   6. +   -
   7. << >>
   8. & ^ |
   9. Comparison operators:> < >= <=
   10. Logical NOT and OR
   11. Lambda expression

The difference between the expression and print execution: the expression enters a single-line command on the command line, such as: >>>a= "Hello" >>>a will have ' hello ' and if print (a), it is hello, without quotation marks.

Small knowledge points in Python