Python built-ins¶
Built-in functions¶
The Python interpreter has a number of functions built into it that are always available. They are listed here in alphabetical order.
| Built-in Functions | ||||
|---|---|---|---|---|
| abs() | divmod() | input() | open() | staticmethod() |
| all() | enumerate() | int() | ord() | str() |
| any() | eval() | isinstance() | pow() | sum() |
| basestring() | execfile() | issubclass() | print() | super() |
| bin() | file() | iter() | property() | tuple() |
| bool() | filter() | len() | range() | type() |
| bytearray() | float() | list() | raw_input() | unichr() |
| callable() | format() | locals() | reduce() | unicode() |
| chr() | frozenset() | long() | reload() | vars() |
| classmethod() | getattr() | map() | repr() | xrange() |
| cmp() | globals() | max() | reversed() | zip() |
| compile() | hasattr() | memoryview() | round() | import() |
| complex() | hash() | min() | set() | |
| delattr() | help() | next() | setattr() | |
| dict() | hex() | object() | slice() | |
| dir() | id() | oct() | sorted() |
For a more detailed description of their usages please see a link python-bult-in-fncts. See also a list of Python built-in keywords Python keywords.
Easily, you can check their help pages using, for example,
help(abs).
Built-in constants¶
The two most frequently used built-in constants in Python include:
| Operation | Result |
|---|---|
| False | The false value of the bool type |
| True | The true value of the bool type |
For a more detailed description of built-in constants please see a link python-bult-in-constants.
Built-in types¶
Boolean operations¶
These are the Boolean operations, ordered by ascending priority:
| Operation | Result |
|---|---|
x or y |
if x is false, then y, else x |
x and y |
if x is false, then x, else y |
not x |
if x is false, then True,
else False |
Comparisons¶
This table summarizes the comparison operations:
| Operation | Meaning |
|---|---|
< |
strictly less than |
<= |
less than or equal |
> |
strictly greater than |
>= |
greater than or equal |
== |
equal |
!= |
not equal |
is |
object identity |
is not |
negated object identity |
Numerics¶
All built-in numeric types support the following operations.
| Operation | Result |
|---|---|
x + y |
sum of x and y |
x - y |
difference of x and y |
x * y |
product of x and y |
x / y |
quotient of x and y |
x // y |
(floored) quotient of x and y |
x % y |
remainder of x / y |
-x |
x negated |
+x |
x unchanged |
abs(x) |
absolute value or magnitude of x |
int(x) |
x converted to integer |
long(x) |
x converted to long integer |
float(x) |
x converted to floating point |
complex(re,im) |
a complex number with real part re, imaginary part im. im defaults to zero. |
c.conjugate() |
conjugate of the complex number c. (Identity on real numbers) |
divmod(x, y) |
the pair (x // y, x % y) |
pow(x, y) |
x to the power y |
x ** y |
x to the power y |
For a more detailed description of built-in types please see a link python-bult-in-types.
An example study¶
The following example shows how to use Python’s built in functions.
- $lecture_note/chapters/chapt03/codes/examples/builtin.py