Chart creation failing with latest Pandas Version

[sunny2309]

Hello PdVega Team,

I am trying to create some charts using PdVega. The current version of pandas on my PC is 1.3.0.

Chart creation using PdVega is failing with below error.

~/anaconda3/lib/python3.7/site-packages/vega3/utils.py in sanitize_dataframe(df)
     38     df = df.copy()
     39 
---> 40     if isinstance(df.index, pd.core.index.MultiIndex):
     41         raise ValueError('Hierarchical indices not supported')
     42     if isinstance(df.columns, pd.core.index.MultiIndex):

AttributeError: module 'pandas.core' has no attribute 'index'

If I change the version to below 1.0.0 (0.25.3 and below) for pandas then only charts are getting created.