[Tutor] Type annotation errors

[boB Stepp]

As I continue to integrate type annotations with David Beazley's
recently released course, "Practical Python Programming", I ran into
another issue.  I have pared down a larger function to just what seems
to be giving the type annotation complaint:

def parse_csv(data_rows: List, has_headers: bool = True) -> List:
    """Parse a CSV file into a list of records."""
    data_rows_iter = iter(data_rows)
    if has_headers:
        headers = next(data_rows_iter)
    records = []
    for row in data_rows_iter:
        if has_headers:
            # Make a dictionary
            record = dict(zip(headers, row))
        else:
            # Otherwise make a tuple
            record = tuple(row)
    records.append(record)

    return records

The complaint is:  test.py|19 col 22 error| Incompatible types in
assignment (expression has type "Tuple[Any, ...]", variable has type
"Dict[Any, Any]")

One of the exercises is to return a list of dictionaries if a csv file
has headers, but if not to return a list of tuples.  mypy apparently
does not like this.  In the "Type hints cheat sheet..." (at
https://mypy.readthedocs.io/en/stable/cheat_sheet_py3.html) in the
section "When you're puzzled or when things are complicated" it
discusses the use of "Any":

"Use Any if you don't know the type of something or it's too dynamic
to write a type for..."

This does not seem particularly complicated to me, so I'm probably
doing something bad or screwy.  Any thoughts?

BTW, the above function works.  If I run it with:

with_headers = [["a", "b", "c"], [1, 2, 3]]
without_headers = [[1, 2, 3]]

my_dict = parse_csv(with_headers)
my_tuple = parse_csv(without_headers, has_headers=False)

print("My dict =", my_dict)
print()
print("My tuple =", my_tuple)

I get my expected result:

bob at Dream-Machine1:~/practical-python/Work$ python3 test.py
My dict = [{'a': 1, 'b': 2, 'c': 3}]

My tuple = [(1, 2, 3)]

-- 
boB