map method in python code example

Example 1: mAPE python

def percentage_error(actual, predicted):
    res = np.empty(actual.shape)
    for j in range(actual.shape[0]):
        if actual[j] != 0:
            res[j] = (actual[j] - predicted[j]) / actual[j]
        else:
            res[j] = predicted[j] / np.mean(actual)
    return res

def mean_absolute_percentage_error(y_true, y_pred): 
    return np.mean(np.abs(percentage_error(np.asarray(y_true), np.asarray(y_pred)))) * 100

Example 2: mapping in python string

# mapping function
def uppercase(u):
    return str(u.upper())

map_iterator = map(uppercase,['a','b','c'])
mylist = list(map_iterator)
print(mylist)

Example 3: map in python 3

map(function, iterable, ...)

Example 4: map function in python

# Python program to demonstrate working 
# of map. 
  
# Return double of n 
def addition(n): 
    return n + n 
  
# We double all numbers using map() 
numbers = (1, 2, 3, 4) 
result = map(addition, numbers) 
print(list(result))

Example 5: map in python

#Syntax
map(functions, iterables)

Example 6: map in python

map(function_to_apply, list_of_inputs)