build_table.py

def build_table(
    field_spec: List[Tuple[str, str, Optional[int]]],
    table: List[Dict[str, str]],
) -> str:
    field_fmts = []
    sep_line_fields = []
    field_names = []
    for name, alignment, width in field_spec:
        if width is None:
            width = max(len(name), *(len(row[name]) for row in table))
        field_fmts.append(f"{{{name}:{alignment}{width}}}")
        sep_line_fields.append("-" * width)
        field_names.append(format(name, f"{alignment}{width}"))
    line_fmt = "".join(("| ", " | ".join(field_fmts), " |"))
    sep_line = "".join(("+-", "-+-".join(sep_line_fields), "-+"))
    header = "".join(("| ", " | ".join(field_names), " |"))
    lines = [line_fmt.format(**row) for row in table]
    return "\n".join((sep_line, header, sep_line, *lines, sep_line))