Hi there, I was learning about the lambda/anonymous functions. And I came across this example which sorts a list:

lst = ["Mouse Keyboard", "Router Hub", "CPU UPS"]
lst.sort(key = lambda each: each.split(" ")[-1].lower())
print(lst)

# Which returns output:-
# ['Router Hub', 'Mouse Keyboard', 'CPU UPS']

I tried to google this but was not successful enough. If someone kindly enlightens me on what the key in the sort() function is for. With the google search, I concluded that it takes a function as input. So, the input here will be the 2nd word of each item in the list. But I'm unable to figure out how the sorting function is performed.

Hi,

So I was doing a code challenge and it's about sorting a string in numerical order based on the integer as part of the string, e.g:

"is2 Thi1s T4est 3a"  -->  "Thi1s is2 3a T4est"

I did it by creating a list with placeholder values and then assigned the values based on the number identified, see:

def order(sentence):
  temp = sentence.split()
  result = [0 for x in range(len(temp))]

  for item in temp:
    for char in item:
      if char.isnumeric():
        num = int(char)
        result[num-1] = item

  return " ".join(result)

I was just looking at other solutions and saw this cool one liner:

return sorted(temp, key=lambda w:sorted(w))

But I don't quite understand how it works :(

I have used the key= argument in the past, for example sorting by the size of the string, i.e key=len

The lambda uses a variable, w and passes it through sorted, but how does that sort by the number included in the string?