in python pls

Here we will write a function variable_encoder ( ) that will use variable keys within the function, such that a new/different key is used for each character to be encoded. This function will have the following input parameters: - input_string | the string to be encoded (str) - start_key | the first value to be used for key within the function (int) - key_increment | the value by which to increment the key each time a character is encoded (int) This code will look very similar to the code for the encoder () question earlier in this assignment. Copy that code in to start and then update to: 1. Have the correct function/parameter names as specified above 2. Before the loop, specify that the value of key should be start_key 3. The loop will contain the same code to encode each character, but you need to add a line within the loop, after the encoding, that updates the key variable by incremening the value in key by the value stored in key_increment Be sure to return the encoded string ( output_string ) from the function