python-cheatsheet

Data structures in Python

Type conversion

Method	Explanation	Usage
type()	Read the type of a variable	type(var)
str()	Set a variable to be a string	string(var)
int()	Set a variable to be an integer (truncate)	int(var)
float()	Set a variable to be a float	float(var)
complex()	Set a variable to be a complex	complex(var)

Arithmetic operations

Method	Explanation	Usage
+	Addition	x+y
-	Subtraction	x-y
*	Multiplication	x*y
/	Division	x/y
%	Modulus (remainder of division)	x%y
**	Exponentiation	x**y
//	Floor division (equivalent to int(x/y))	x//y

Random values

[TBD]

Assignment operations

Method	Explanation	Usage
=	Assign value to variable	x=value
+=	Equivalent to x=x+value	x+=value
-=	Equivalent to x=x-value	x-=value
*=	Equivalent to x=x*value	x*=value
/=	Equivalent to x=x/value	x/=value
**=	Equivalent to x=x**value	x**=value
//=	Equivalent to x=x//value	x//=value

Comparison operations

Method	Explanation	Usage
==	Equal to	x==y
!=	Not equal to	x!=y
>	Greater than	x>y
<	Less than	x<y
>=	Greater than or equal to	x>=y
<=	Less than or equal to	x<=y
and	If both statements are true = true	x=y and y=z
or	If one of the statements is true = true	x=y or y=z
not	Reverse the result	not(x=y)
is	Strict equality (same object)	x is y
is not	Reverse strict equality (not same object)	x is not y
in	Sequence is present in object	x in y
not in	Sequence is not present in object	x not in y

List operations

Method and usage	Explanation
list=["value1","value2"]	Define a list
list[index]	Read value of list at index (starts at 0) (can be negative)
list[index]=value	Update the value at index index with value value
list.append(value)	Add items to the end of the list
list.extend(sequence)	Add a sequence of items at the end
list.insert(index,value)	Insert value at index index
list.remove(value)	Remove the first item with value value
list.pop(index)	Remove the value at index and return it. Default index: -1
list.sort(reverse=Bool, key=funct)	Sort the list. Default Bool: false. Default key: ascending
list.reverse()	Reverses the order of the list
len(list)	Returns the length of the list
`list.count(value)	Returns how many times a value appears in the list

Tuple operations

Method and usage	Explanation
tuple=("value",value, value, "value")	Define a tuple
tuple[index]	Read value of tuple at index (starts at 0)(can be negative)
tuple+tuple2	Concatenate tuples
del tuple	Deletes the entire tuple
len(tuple)	Returns the length of the tuple
`tuple.count(value)	Returns how many times a value appears in the tuple

Set operations

Method and usage	Explanation
tuple=("value",value, value, "value")	Define a tuple
tuple[index]	Read value of tuple at index (starts at 0)(can be negative)
tuple+tuple2	Concatenate tuples
del tuple	Deletes the entire tuple
len(tuple)	Returns the length of the
`tuple.count(value)	Returns how many times a value appears in the tuple
list.index(value)	Return the first index with value value

Dictionary operations

Method and usage	Explanation
dict={"Key": value,"Key": value}	Define a dictionary
dict=dict(Key=value, Key=value)	Define a dictionary without quoting the keys
dict[key]=value	Modify the value of an existing value or create a new one
del dict[key]	Remove the key key and associated value
dict.update(pairs)	Inserts items to the dictionary. Can add multiple at the same time
dict[key]	Return the value of key item
dict.get(key)	Return the value of key item
dict.setdefault(key,value)	Return the value of key item. If key item does not exist, insert key with value.
dict.keys()	Return a tuple containing a list of keys. Updates automatically.
dict.values()	Return a tuple containing a list of values. Updates automatically.
dict.items()	Return a tuple containing a list of key-value pairs. Updates automatically.
dict.pop(key)	Removes the specified item, returns the removed value
dict.popitem()	Removes the last item inserted, returns the removed value
len(dict)	Return the length of a dictionary or tuple
dict.clear()	Clear the entire dictionary.