Python indentation and Process Control statements

1. Indent: Indentation is the only way Python represents a block of statements;

All statements in a block of statements must use the same indentation, representing a contiguous sequence of logical lines;

The first line of the source file does not need to be indented (it is not allowed to start with any spaces);

The standard Python style is to use 4 spaces per indentation level;

How to represent a logical line across rows:

(1) ' \ ' can connect two adjacent physical lines into a logical line;

(2) [], {}, () can cross the physical line;

(3) Triple quotation string constants (including single and double quotes) can also span multiple lines, but one thing must be noted: when wrapping, you need to add the ' \ ' slash at the end of the physical line, otherwise the newline character will be included;

2.if statement:

The basic form is:

If judging condition:
Execute statement ...
Else
Execute statement ...

3.while Loop statement:

The basic form is:

While judging condition:
Execute statement ...

4.for Loop statement:

The basic form is:

For Iterating_var in sequence:
Statements

5.break statement:

Used to terminate the loop statement, that is, the loop condition does not have a false condition or the sequence has not been fully recursive, will also stop the execution of the loop statement;

6.continue statement:

Used to tell Python to skip the remaining statements of the current loop, and then proceed to the next round of loops;

The difference between range and xrange:

The xrange usage is exactly the same as range, and the difference is not a list object, but a generator.

When generating a large sequence of numbers, using xrange will be much better than range performance, because there is no need to open up a large amount of memory space.

Python indentation and Process Control statements