I need to group the dataframe and add a new column 'Amount' where the number of records repetitions will be displayed. Some like fun. count() in sql or summarise (https://dplyr.tidyverse.org/reference/summarise.html) in R
How I can do this in pandas?
a = [{'order': '789', 'name': 'A', 'date': 20220501}, {'order': '456', 'name': 'B', 'date': 20220502}, {'order': '704', 'name': 'C', 'date': 20220503}, {'order': '789', 'name': 'A', 'date': 20220501}, {'order': '789', 'name': 'A', 'date': 20220501}, {'order': '704', 'name': 'C', 'date': 20220503}]
df = pd.DataFrame(a)
df = df.groupby(['order', 'name', 'date']).sum().reset_index()
print(df)
I need the next result: