CODEWITHSUNDEEP
pythonpandas
user3294779
user3294779

Reputation: 623

Conditionally update Data Frame column

I'm trying to update a column from a value of 0 to a value of 1 if certain conditions are true. Here is my code:

df_['win'] = 0
df_.loc[df_['predicted_spread'] > df_['vegas_spread'] and df_['actual_spread'] > df_['vegas_spread'], 'win'] = 1

This is the error I'm getting:

ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().

Does anybody have any ideas of what's going on here?

Upvotes: 0

Views: 85

Answers (2)

shawnheide
shawnheide

Reputation: 807

When doing boolean indexing you need to use the logical operator for and which is &. See the doc here for more info

df['win'] = 0
cond_1 = df['predicted_spread'] > df['vegas_spread']
cond_2 = df['actual_spread'] > df['vegas_spread']
df.loc[cond_1 & cond_2, 'win'] = 1

Basically just your answer with & instead of and. I just rewrote it to make it a little clearer.

Upvotes: 1

piRSquared
piRSquared

Reputation: 294258

Try

df_['win'] = 0
df_.loc[df_['predicted_spread'].gt(df_['vegas_spread']) and df_['actual_spread'].gt(df_['vegas_spread']), 'win'] = 1

Upvotes: 1

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