Solution

You MUST first check the type of ticker_add.

type(ticker_add)

Adding new row to a dataframe

1. Assuming your ticker_add is a dictionary with the column names of the dataframe df as the keys, you can do this:

   df.append(pd.DataFrame(ticker_add))
   

2. Assuming it is a single non-array-like input, you can do this:

   # adds a new row for a single column ("Ticker") dataframe
   df = df.append({'Ticker': ticker_add}, ignore_index=True)
   

References

1. Add one row to pandas DataFrame
2. https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.append.html