How do you choose a unique line of time among the same lines?

[Kadyn]

There's a lot of lines that have the same lines on the column 'name', but they have different dates.

I just need to keep that line from every group where the date is fresh. I've been trying to do this for six hours, but I'm not successful. Any idea, please?

[charlenef]

Module management https://pandas.pydata.org/pandas-docs/stable/user_guide/10min.html :

• Read Excel file in Pandas DataFrame
• We'll sort out the dates.
• grouping classified names
• select only one last line from each group.
• Maintain the result of the new Excel file.

Example:

import pandas as pd
df = pd.read_excel("filename.xlsx")

res = df.sort_values("date").groupby("name", as_index=False).last(1)

res.to_excel("result.xlsx", index=False)

Example of data:

  name        date

0  aaa  2021-10-10

1  bbb  2020-01-01

2  aaa  2021-09-09

3  bbb  2020-02-02

4  ccc  2000-12-31

result:

In [223]: df.sort_values("date").groupby("name", as_index=False).last(1)

Out[223]:

name        date

0  aaa  2021-10-10

1  bbb  2020-02-02

2  ccc  2000-12-31

---

Example of decision for published file:

import pandas as pd

df = pd.read_excel("test2.xlsx", parse_dates=["Время договора"])

res = df.groupby("Наименование инструмента", as_index=False).apply(lambda x: x.nlargest(1, "Время договора"))

res.to_excel("result.xlsx", index=False)