span_table.py

table_structure = [
    [('A', 3, 1), ('B', 1, 2), ('C', 3, 1)],
    [('D', 1, 1), ('E', 2, 1)],
    [('F', 2, 1)],
    [('G', 1, 2), ('H', 1, 2)],
]

total_cols = sum(x[2] for x in table_structure[0])
table = [[None]*total_cols for _ in range(len(table_structure))]

for row_idx, row in enumerate(table_structure):
    col = 0
    while table[row_idx][col] is not None:
        col += 1
    for cell in row:
        text, rowspan, colspan = cell
        for r in range(rowspan):
            for c in range(colspan):
                table[row_idx+r][col+c] = text
        col += colspan

for row in table:
    print(row)