Error on streamlit app.py

[reejungkim]

Key error 'Date'

File
"/app/.heroku/python/lib/python3.7/site-packages/streamlit/script_runner.py",line 332, in _run_script
exec (code, module._dict
File "/app/app.py", line 126, in ‹module>
df = df.loc[df[ 'Date']. notnull0]
File "/app/.heroku/python/lib/python3.7/site-packages/pandas/core/frame.py", line 2902, in _getitem
indexer = self.columns.get_loc(key)
File "/app/.heroku/python/lib/python3.7/site-packages/pandas/core/indexes/base.py", line 2891, in get_loc
raise KeyError(key) from err