Example of callbacks with Python

callback.py

# Example of using callbacks with Python
#
# To run this code
#   1. Copy the content into a file called `callback.py`
#   2. Open Terminal and type: `python /path/to/callback.py`
#   3. Enter

def add(numbers, callback):
    results = []
    for i in numbers:
        results.append(callback(i))
    return results

def add2(number):
    return number + 2

def mul2(number):
    return number * 2

print add([1,2,3,4], add2) #=> [3, 4, 5, 6]
print add([1,2,3,4], mul2) #=> [2, 4, 6, 8]

Can't you just use map() in the add() function?

Then first parameter will work as callback

Same code using map

def add2(number):
    return number + 2

def mul2(number):
    return number * 2

print(list(map(add2, [1, 2, 3, 4]))) # [3, 4, 5, 6]
print(list(map(mul2, [1, 2, 3, 4]))) # [2, 4, 6, 8]

Short version:

print(list(map(lambda x: x + 2, [1, 2, 3, 4]))) # [3, 4, 5, 6]
print(list(map(lambda x: x * 2, [1, 2, 3, 4]))) # [2, 4, 6, 8]

Thx a lot ^)

Thanks a lot. I am learning callback function.