Question

Using Python Programming Language:

3. Write a function flatten that takes a 2D list and returns all the items of each list concatenated together into one new 1D list. For example: flatten ([["a", "b"],["c","0"],["e","f"]]) would return ["a", "b","C","d", "e","f"] Save the function in a PyDev library module named functions.py Write a program t03.py that tests flatten function and prints the returned flat list to the screen. Test your program with a different list, hardcoded in t03.py • Copy the results to testing.txt.

Answer 1

Define a function flatten() that accepts a 2D list

1. define a function flatten()
2. Initialize a new list return_list as empty list
3. For each list in 2D list,
4. Add all the elements in inner list to return_list using the funtion extend() of list class
5. return return_list

Program:

Note: Please double-check the indentation using the screenshot provided as a reference.

def flatten(list_items):                # function faltten() that accepts a 2D list
        result_list = []                        # initialize return_list as empty list
        for item in list_items:         # iterate over each list in list_items
                result_list.extend(item) # add each items in inner list to result_list
        return result_list                      # return resurn_list

print(flatten([["a","b"],["c","d"],["e","f"]])) # prints ['a', 'b', 'c', 'd', 'e', 'f']

Screenshot:

def flatten(List_items): # function faltten() that accepts a 2D list result_list = [] # initialize return_list as empty list for item in list_items: # iterate over each list in list_items result_list.extend(item) # add each items in inner list to result_list return result_list # return resurn_list print(Flatten([["a","6"],["","d"],["","f"]])) # prints ['a', 'b', 'c': 'd', 'e', 'f']

Output:

['a', 'b', 'c', 'd', 'e', 'f']

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