Pandas: if the word "Action" precedes the word "Dialouge", fill the timeline of-CodePudding

I am trying to make the value of Action timeline = Dialogue timeline, only if Action comes before dialogue:

x = []
for i in range(len(df)):
    if df['Type'][i] == "Action" < df['Type'][i] == "Dialouge":
        x.append(df['Timeline'])[enter image description here][1]

CodePudding user response：

You can set a boolean mask on the conditions, then set the rows of column Timeline fulfilling the conditions to the corresponding values of next rows by .loc and .shift(), as follows:

(Note the spelling/mispelling if the word Dialouge (rather than Dialogue) in the sample data)

mask = (df['Timeline'].isna() | (df['Timeline'] == '')) & (df['Type'] == "Action") & (df['Type'].shift(-1) == "Dialouge")

df.loc[mask, 'Timeline'] = df['Timeline'].shift(-1)

Data Input:

       Type  Timeline
0    Action       NaN
1  Dialouge  00:05:54
2    Action       NaN
3  Dialouge  00:06:06
4    Action       NaN
5  Dialouge       NaN

Output:

print(df)

       Type  Timeline
0    Action  00:05:54
1  Dialouge  00:05:54
2    Action  00:06:06
3  Dialouge  00:06:06
4    Action       NaN
5  Dialouge       NaN