Fix pandas copy/slice warning.

[snippsat]

Try change to this.
SettingWithCopyWarning is generated by pandas when you are modifying a DataFrame that is actually a view of another DataFrame
By using .copy() to make a copy of the DataFrame before modifying it,should avoid the SettingWithCopyWarning.
This ensures that are working on a new DataFrame rather than inadvertently modifying the original one.

# Make supplier table.  Supplier table contains rows from product_table
# where one of the words in the description matches a supplier code.
supplier_table = product_table[["Description"]].copy()
supplier_table["Product"] = supplier_table["Description"].map(find_supplier)
supplier_table = supplier_table[~supplier_table["Product"].isna()]
supplier_table = supplier_table[["Product", "Description"]]
print(supplier_table)