理解Python中raise、assert語句

• 7. Simple statements

  A simple statement is comprised within a single logical line.

  Several simple statements may occur on a single line separated by semicolons.

  The syntax for simple statements is :

  simple_stmt ::= expression_stmt
                  | assert_stmt
              	| assignment_stmt
                  | augmented_assignment_stmt
                  | annotated_assignment_stmt
                  | pass_stmt
                  | del_stmt
                  | return_stmt
                  | yield_stmt
                  | raise_stmt
                  | break_stmt
                  | continue_stmt
                  | import_stmt
                  | future_stmt
                  | global_stmt
                  | nonlocal_stmt
  

• 7.1 Expression statements

• 7.2 Assignment statements

  Assignment statements are used to (re)bind names to values to modify attributes or items of mutable objects.

• 7.3 The assert statement

  Assert statements are a convenient way to insert debugging assertions into a program.

• 7.4 The pass statement

  pass is a null operation , which means when it is executed, nothing happens.

• 7.5 The del statement

• 7.6 The return statement

• 7.7 The yield statement

• 7.8 The raise statement

  If no expressions are present, raise re-raise the last exception that was active in the current scope. If no exception is active in the current scope, a RuntimeError exception is raised indicating that this is an error.

  From tutorial, definition of raise is :

  The raise keyword is used to raise an exception. You can define what kind od error to raise, and the text to

• 7.9 The break statement

• 7.10 The continue statement

• 7.11 The import statement

• 7.12 The global statement

• 7.13 The nonlocal statement

• References

1. Python Tutorial