forecasting values for each category using Prophet in python

Question

I am very new to doing time series in Python and Prophet. I have a dataset with the variables article code, date and quantity sold. I am trying to forecast the quantity sold

Answer 1

I know this is old, but I faced a similar problem and this worked for me:

df = pd.read_csv('file.csv')
df = pd.DataFrame(df)
df = df.rename(columns={'Date of the document': 'ds', 'Quantity sold': 'y', 'Article bar code': 'Article'})
#I filter first Articles bar codes with less than 3 records to avoid errors as prophet only works for 2+ records by group
df = df.groupby('Article').filter(lambda x: len(x) > 2)

df.Article = df.Article.astype(str)

final = pd.DataFrame(columns=['Article','ds','yhat'])

grouped = df.groupby('client_id')
for g in grouped.groups:
    group = grouped.get_group(g)
    m = Prophet()
    m.fit(group)
    future = m.make_future_dataframe(periods=365)
    forecast = m.predict(future)
    #I add a column with Article bar code
    forecast['Article'] = g
    #I concad all results in one dataframe
    final = pd.concat([final, forecast], ignore_index=True)

final.head(10)