Python map
Map Function in Python
In this tutorial, we will learn about the Python map() function with the help of examples.
The map() function executes a specified function for each item in an iterable and returns an iterators.
Syntax
map(function, iterables)
Map Python
Parameter
- function (Required) : The function to execute for each item
- iterable (Required): An iterable like sets, lists, tuples, etc
python list map
Returns
- The
map()
function is going to apply the given function on all the items inside the iterator and return an iterable map object,example tuple, a list, etc. - The map function, allows us to apply the same operation to each element and return a new list of elements receiving the modified elements from this operation.
Map in Python
Imagine that we have a list of names.
names = ['RadCliffe', 'Craig', 'Dae Kim', 'Gilles', 'Sharman']
Now we can iterate through the names one by one, add the first name “Daniel”.
def addDaniel(name): return "Daniel " + name
print(map(addDaniel, names)) # <map object at 0x7f1e182ec1f0>
Python Map Function
The map function returns a map object. So, in order to get our desired list back, we need to coerce the map object to a list.
print(list(map(addDaniel, names)))
[ 'Daniel RadCliffe', 'Daniel Craig', 'Daniel Dae Kim', 'Daniel Gilles', 'Daniel Sharman' ]
Map Function Python
- So the map function goes through each element and executes the altering function on the current element.
- Then the return value of the altering function is added as an element to the new list.
python map()
def add(n): return n + n numbers = (9, 5, 7, 3) result = map(add, numbers) print(list(result)) # [18, 10, 14, 6]
python map list
def myfunc(n): return len(n) names = ['RadCliffe', 'Craig', 'Dae Kim', 'Gilles', 'Sharman'] print(list(map(myfunc, names))) # [9, 5, 7, 6, 7]