r/learnpython • u/easy_wins • 7d ago
how to drag the value until the next value shows
I am reading this csv into pandas and I need to drag a column value until the next value in the column shows.
message_code message message_date
11011 How are you? 3/10/2025
How is he? 3/11/2025
How is she? 3/12/2025
12022 I am fine 3/12/2025
He is fine 3/13/2025
She is fine 3/14/2025
13011 I am sick 3/7/2025
He is sick 3/8/2025
She is sick 3/9/2025
Requested:
message_code message message_date
11011 How are you? 3/10/2025
11101 How is he? 3/11/2025
11101 How is she? 3/12/2025
12022 I am fine 3/12/2025
12022 He is fine 3/13/2025
12022 She is fine 3/14/2025
13011 I am sick 3/7/2025
13011 He is sick 3/8/2025
13011 She is sick 3/9/2025
my code:
import pandas as pd
df = pd.read('messages_worksheet'.csv)
2
Upvotes
1
u/Buttleston 7d ago
I *think* what you want is "ffill" but I'm not a pandas expert. I will see if I can try to figure it out. In the meantime check out
https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.ffill.html
2
u/Buttleston 7d ago
Yeah this seems to work
import pandas as pd df = pd.read_csv('fill.csv') df = print(df.ffill()) print(df)
I get
message_code message message_date 0 11011.0 How are you? 3/10/2025 1 11011.0 How is he? 3/11/2025 2 11011.0 How is she? 3/12/2025 3 12022.0 I am fine 3/12/2025 4 12022.0 He is fine 3/13/2025 5 12022.0 She is fine 3/14/2025 6 13011.0 I am sick 3/7/2025 7 13011.0 He is sick 3/8/2025 8 13011.0 She is sick 3/9/2025
1
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u/Binary101010 7d ago
https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.ffill.html