sorted(arr, key=lambda x:(self.function(x), x))

What's the meaning of (self.function(x), x)?

CodePudding user response：

This allows sorting by two criteria. If two values are equal for self.function(x), they will be sorted by x.

CodePudding user response：

The key parameter of the sorted method takes in a function reference that returns a key to be used for sorting purposes.

as an example

arr = ["apple", "Andrew", "Cat", "cool"]
print(sorted(arr, key=lambda item: item.lower()))

would sort the items in the arr based on their str.lower representation.

the following snippet

sorted(arr, key=lambda x:(self.function(x), x))

sorts the items in arr based on the tuple (self.function(x), x), see this post to see how python sorts an array of tuples.