OperationalError 1241: Operand should contain 1 column(s)

Question

Code:

import pandas as pd
df = pd.DataFrame(list(inverted_index.items()),columns = ['words','docids']) 
from pandas.io import sql
from sqlalchemy import create_engine
engine = create_engine("mysql+pymysql://{user}:{pw}@localhost/{db}"
                       .format(user="root",
                               pw="shreshre",
                               db="nltk"))
df.to_sql(con=engine, name='documents', if_exists='replace')

Output:

Here I want convert my inverted index, which is in dictionary type, into a dataframe and write it in MySQL. But I am receiving an error:

OperationalError: (pymysql.err.OperationalError) (1241, 'Operand should contain 1 column(s)')
[SQL: INSERT INTO documents (`index`, words, docids) VALUES (%(index)s, %(words)s, %(docids)s)]
[parameters: ({'index': 0, 'words': 'bank', 'docids': {0, 1, 2, 3, 4, 17, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 37, 38, 39, 40, 41, 43, 44, 45, 46, 48, 52, 53, 54, 55, 56, 59, 60, 62, 64, 66, 67, 68, 69 ... (1314 characters truncated) ...  719, 720, 721, 722, 724, 726, 728, 733, 734, 735, 736, 737, 739, 740, 743, 746, 748, 752, 753, 755, 756, 757, 758, 759, 762, 765, 766, 767, 768, 772}}, {'index': 1, 'words': 'defin', 'docids': {0, 2, 354, 612, 773, 76, 84}}, {'index': 2, 'words': 'establish', 'docids': {0, 161, 391, 328, 330, 718, 719, 720, 722, 245, 217, 411, 156}}, {'index': 3, 'words': 'custodi', 'docids': {0, 405}}, {'index': 4, 'words': ',', 'docids': {0, 1, 2, 3, 8, 14, 17, 20, 22, 24, 25, 26, 27, 30, 31, 41, 43, 45, 48, 49, 51, 52, 54, 55, 59, 62, 63, 65, 67, 69, 70, 72, 73, 74, 76, 78, 79, 80, 81 ... (1428 characters truncated) ...  705, 706, 708, 710, 711, 712, 716, 718, 719, 721, 722, 724, 729, 730, 732, 735, 736, 741, 743, 745, 749, 756, 757, 758, 762, 766, 768, 769, 771, 773}}, {'index': 5, 'words': 'loan', 'docids': {0, 512, 517, 519, 538, 29, 33, 34, 557, 558, 47, 559, 564, 574, 578, 580, 70, 73, 76, 79, 616, 621, 113, 114, 115, 116, 117, 123, 124, 127, 128, 129, ... (75 characters truncated) ...  711, 200, 219, 227, 228, 234, 235, 241, 758, 771, 309, 310, 340, 343, 346, 349, 354, 365, 368, 380, 383, 384, 385, 386, 440, 447, 448, 451, 453, 474}}, {'index': 6, 'words': 'exchang', 'docids': {0, 416, 290, 354, 357, 425, 10, 302, 430, 405, 376, 415}}, {'index': 7, 'words': 'issu', 'docids': {0, 386, 419, 676, 390, 397, 302, 272, 274, 306, 722, 700, 350}}  ... displaying 10 of 1969 total bound parameter sets ...  {'index': 1967, 'words': '86', 'docids': {774}}, {'index': 1968, 'words': 'separ', 'docids': {774}})]

I am not able to understand the existing solution posted on Stackoverflow regarding a similar error. Someone please help me out.