To convert a map object to a list in Python, you can use the list() method or use the iterable unpacking operator “*“. Follow the article to understand better.
What is the map() function in Python?
In Python, the built-in map() function iterates the elements of an iterable( list, tuple, dict, set,…) through a given function (e.g. chr(),… ) and returns a list of results when it’s done. You use this function when you want to use a single function to convert for all iterable elements. Iterable and function are passed as arguments to map() in Python.
Syntax:
map(function, iterable, …)
The map() function returns values called map object.
Example:
numTuple = (1, 2, 3, 4, 5) resultMap = map(int, numTuple) print(type(resultMap)) # <class 'map'>
The problem here is I want to convert a map object to a list.
Convert a map object to a list in Python
Use the list() method
In Python, ‘ list’ is a data type to archive many other types of data and is allowed access to the elements in the ‘list’. A ‘list’ can include data types such as integers, strings, and objects. ‘List’ is mutable even when created. The elements in the ‘list’ are ordered and have a certain number. The elements in ‘list’ are indexed in a sequence, and by default, the first index of the list is 0.
Syntax:
list([iterable])
Parameters:
- iterable (optional): the object can be a string, tuple, set, dictionary, or iterator.
The list() function returns:
- list() creates an empty list if no parameters are passed.
- list() creates a list of elements in the iterable if the iterable is passed as a parameter.
Example:
numTuple = (1, 2, 3, 4, 5)
resultMap = map(int, numTuple)
# Using list() to convert map object to a list
resultList = list(resultMap)
print(f"resultList: {resultList}")
print(f"Type of resultList: {type(resultList)}")Output:
resultList: [1, 2, 3, 4, 5]
Type of resultList: <class 'list'>The example above map() function returns the squared values of the iterable ‘numTuple‘. The values [1, 2, 3, 4, 5] are called map objects, and then I take the map object passed in ‘list’ and output ‘list’ to the screen.
Use the iterable unpacking operator “*”
The * is used as the iterable unpacking operator. The advantage of using the * operator is that you can unpack lists and other containers like tuple, string, generator, dict, and set.
Example:
numTuple = (1, 2, 3, 4, 5)
# Using the * operator to convert map object to list
resultList = [*map(int, numTuple)]
print(f"resultList: {resultList}")
print(f"Type of resultList: {type(resultList)}")Output:
resultList: [1, 2, 3, 4, 5]
Type of resultList: <class 'list'>In the above example, I use the unpacking operator ‘*’ to unpack an iterable in the map() function.
Summary
If you have any questions about how to convert a map object to a list in Python, leave a comment below. I will answer your questions. Thank you for reading!
Maybe you are interested:
- Create a list with same value repeated N times in Python
- Join a list of lists in Python
- Multiply each element in a list by a number in Python
My name is Jason Wilson, you can call me Jason. My major is information technology, and I am proficient in C++, Python, and Java. I hope my writings are useful to you while you study programming languages.
Name of the university: HHAU
Major: IT
Programming Languages: C++, Python, Java
