and |
logical and in conditional expressions |
as |
follows the with statement or import statement
assigns a name
|
assert |
insert debugging assertions into a program
assert_stmt ::= "assert" expression ["," expression ]
|
break |
It terminates the nearest enclosing loop
- in for loop, break keeps current value of the iteration variable
- in try with finally, the finally clause is executed before leaving the loop
break_stmt ::= "break"
|
class |
defines a class object
classdef ::= "class" classname [inheritance ] ":" suite
inheritance ::= "(" [expression_list ] ")"
classname ::= identifier
|
continue |
It continues with the next cycle of nearest enclosing for or while loop
- in try with finally, the finally clause is executed before leaving the loop
|
def |
Defines a function
def whats_on_the_telly(penguin=None):
if penguin is None:
penguin = []
penguin.append("property of the zoo")
return penguin
|
del |
Delete variables, opposite of assignment. e.g.
>>> t = ['a', 'b', 'c']
>>> del t[1]
>>> print t
['a', 'c'] |
>>> t = ['a', 'b', 'c', 'd', 'e', 'f']
>>> del t[1:5]
>>> print t
['a', 'f'] |
del t[0] |
|
elif |
used in if block |
else |
used within if block |
except |
used with try block |
exec |
executes the string that follows as python code.
exec_stmt ::= "exec" or_expr ["in" expression ["," expression ]]
|
finally |
used in try block |
for |
used to iterate over the elements of a sequence (such as a string, tuple or list) or other iterable object:
for_stmt ::= "for" target_list "in" expression_list ":" suite
["else" ":" suite ]
|
from |
|
global |
declares the identifiers that follow as global for the entire code block.
global_stmt ::= "global" identifier ("," identifier )*
|
if |
used for conditional execution
if_stmt ::= "if" expression ":" suite
( "elif" expression ":" suite )*
["else" ":" suite ]
|
import |
imports external modules into your code
import_stmt ::= "import" module ["as" name ] ( "," module ["as" name ] )*
| "from" relative_module "import" identifier ["as" name ]
( "," identifier ["as" name ] )*
| "from" relative_module "import" "(" identifier ["as" name ]
( "," identifier ["as" name ] )* [","] ")"
| "from" module "import" "*"
module ::= (identifier ".")* identifier
relative_module ::= "."* module | "."+
name ::= identifier
|
in |
|
is |
|
lambda |
|
not |
|
or |
|
pass |
is a null operation - nothing happens when it is executed. Useful as placeholder when a statement is required syntactically but no code needs to be execuoted |
print |
evaluates each expression and writes the result to standard output
print_stmt ::= "print" ([expression ("," expression )* [","]]
| ">>" expression [("," expression )+ [","]])
|
raise |
raise_stmt ::= "raise" [expression ["," expression ["," expression ]]]
If no expressions are present, raise re-raises the last exception that was active in the current scope. If no exception is active in the current scope, a TypeError exception is raised indicating that this is an error (if running under IDLE, a Queue.Empty exception is raised instead).
|
return |
it leaves the current function call with the expression list (or None) as the return value
return_stmt ::= "return" [expression_list ]
|
try |
specifies exception handlers and/or cleanup code for a group of statements:
try_stmt ::= try1_stmt | try2_stmt
try1_stmt ::= "try" ":" suite
("except" [expression [("as" | ",") identifier ]] ":" suite )+
["else" ":" suite ]
["finally" ":" suite ]
try2_stmt ::= "try" ":" suite
"finally" ":" suite
|
while |
used for repeated execution as long as an expression is true
while_stmt ::= "while" expression ":" suite
["else" ":" suite ]
|
with |
used to wrap the execution of a block with methods defined by a context manager. This allows common try...except...finally usage patterns to be encapsulated for convenient reuse.
with_stmt ::= "with" with_item ("," with_item)* ":" suite
with_item ::= expression ["as" target ]
|
yield |
The yield statement is only used when defining a generator function, and is only used in the body of the generator function. Using a yield statement in a function definition is sufficient to cause that definition to create a generator function instead of a normal function
# to put an example here #
|