Python Reference

Built-in functions and the methods of strings, lists, dictionaries and sets.

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Name	Group	Description
print()	Built-in	Prints values to the screen.
input()	Built-in	Reads a line typed by the user.
len()	Built-in	The number of items in a sequence or collection.
type()	Built-in	The type of a value.
int()	Built-in	Converts a value to an integer.
float()	Built-in	Converts a value to a decimal number.
str()	Built-in	Converts a value to a string.
bool()	Built-in	Converts a value to True or False.
list()	Built-in	Makes a list.
tuple()	Built-in	Makes a tuple.
set()	Built-in	Makes a set of unique values.
dict()	Built-in	Makes a dictionary.
range()	Built-in	A sequence of numbers.
sum()	Built-in	The sum of an iterable of numbers.
min()	Built-in	The smallest item.
max()	Built-in	The largest item.
abs()	Built-in	The absolute value.
round()	Built-in	Rounds a number.
pow()	Built-in	Raises to a power.
divmod()	Built-in	Quotient and remainder.
sorted()	Built-in	A new sorted list.
reversed()	Built-in	An iterator over items in reverse.
enumerate()	Built-in	Pairs each item with its index.
zip()	Built-in	Pairs items from several iterables.
map()	Built-in	Applies a function to every item.
filter()	Built-in	Keeps items where the function is true.
any()	Built-in	True if any item is true.
all()	Built-in	True if every item is true.
isinstance()	Built-in	Whether an object is of a type.
open()	Built-in	Opens a file.
str.upper()	String	Upper-case copy of a string.
str.lower()	String	Lower-case copy of a string.
str.title()	String	Capitalises each word.
str.strip()	String	Removes whitespace from both ends.
str.split()	String	Splits a string into a list.
str.join()	String	Joins items with a separator.
str.replace()	String	Replaces text.
str.find()	String	Index of the first match, or -1.
str.startswith()	String	Whether a string starts with text.
str.endswith()	String	Whether a string ends with text.
str.count()	String	Counts occurrences.
str.format()	String	Fills in placeholders.
str.isdigit()	String	Whether all characters are digits.
str.zfill()	String	Pads with zeros on the left.
list.append()	List	Adds an item to the end.
list.extend()	List	Adds all items of another iterable.
list.insert()	List	Inserts an item at an index.
list.remove()	List	Removes the first matching item.
list.pop()	List	Removes and returns an item.
list.sort()	List	Sorts the list in place.
list.reverse()	List	Reverses the list in place.
list.index()	List	The index of the first match.
list.count()	List	Counts occurrences.
list.copy()	List	A shallow copy.
dict.get()	Dictionary	A value, or a default if missing.
dict.keys()	Dictionary	The keys.
dict.values()	Dictionary	The values.
dict.items()	Dictionary	Key and value pairs.
dict.update()	Dictionary	Merges another dictionary in.
dict.pop()	Dictionary	Removes a key and returns its value.
dict.setdefault()	Dictionary	Gets a key, adding it if missing.
set.add()	Set	Adds an item.
set.union()	Set	All items from both sets.
set.intersection()	Set	Items in both sets.
set.difference()	Set	Items in a but not in b.
f-string	Syntax	A string with expressions inside braces.
list comprehension	Syntax	Builds a list in one line.
lambda	Syntax	A small anonymous function.
try / except	Syntax	Handles errors.
import	Syntax	Loads a module.
math.sqrt()	math	The square root.
math.ceil()	math	Rounds up.
math.floor()	math	Rounds down.
math.pi	math	The value of pi.
random.choice()	random	A random item from a sequence.
random.randint()	random	A random integer in a range.
datetime.date	datetime	Work with dates.
json.dumps()	json	Converts data to JSON text.
json.loads()	json	Converts JSON text to data.