functions.py

#### Function Examples ####

## New Function Introduction: isinstance(variable, type)
## Given a variable (e.g.: a,b,c) and a specific type (int, float, bool, str, list, dict, etc)
## isinstance(variable, type) checks if variable is of the specified type and returns True or False
## e.g.: 
## a = 1 
## isinstance(a, int) --returns--> True
## isinstance(a, str) --returns--> False
## Note the following:
## a = True
## isinstance(a, int) --returns--> True
## isinstance(a, bool) --returns--> True

## Retains only numbers in a given list, numbers must be converted to float type

def keep_numbers(my_list):
    my_new_list = list()
    
    for idx, item in enumerate(my_list):
        if isinstance(item, int) or isinstance(item, float): # check if its any numerical type, incl boolean
            my_new_list.append( float(item) )
        elif isinstance(item, str): # is string 
            if item.isdigit():
                my_new_list.append( float(item) )
        # all other types will be ignored e.g. list, dict, tuple, etc
    # done loop checking
    return my_new_list


def sum_all_items(my_list):
    pass
    # TODO: Sum all items in a cleaned list

## TODO
## 1. Implement keep_strings function 




a = [1,2,'123', '123a', 'abcde', True, False, 'can i has cake']
b = [234, 567, "five", "six", "seven", ['abc','def'], False, 888]

cleaned_list_a = keep_numbers(a)
cleaned_list_b = keep_numbers(b)

print(cleaned_list_a)
print(cleaned_list_b)


## The following will not run correctly if sum_all_items() is not implemented
# sum_a = sum_all_items(cleaned_list_a)
# sum_b = sum_all_items(cleaned_list_b)

# print(f'Sum of list a: {sum_a}')
# print(f'Sum of list b: {sum_b}')