CODEWITHSUNDEEP
pythonpandasdataframe
Yami Kanashi
Yami Kanashi

Reputation: 151

Replacing the corresponding column values in Python Pandas dataframe

I have a data frame, say :

  Name  Visits
0 Z      0
1 A      0
2 B      1
3 C      1
4 D      0
5 E      0

Now, I made a list with those names whose visits are 0, so it has Z, A, D, and E. Now, I randomly choose 2 names from these 4. Then, I want to increase the visits of these 2 people by 1. How do I reference only these 2 names, access their corresponding visits and alter it? [In python, Pandas] Thank you!

Upvotes: 1

Views: 75

Answers (3)

BENY
BENY

Reputation: 323396

Try random.choice from number then assign value by index

df.loc[np.random.choice(df.index[df.Visits==0],2),'Visits'] += 1
df
Out[95]: 
  Name  Visits
0    Z       1
1    A       0
2    B       1
3    C       1
4    D       0
5    E       0

Upvotes: 1

Ch3steR
Ch3steR

Reputation: 20689

If you already have list of who visited 0 times you can use pd.Series.isin to create a boolean mask for boolean indexing then increase corresponding values by 1

vals = ['Z', 'A', 'D', 'E']
m = df['Name'].isin(vals)
df.loc[m, 'Visits']+=1
# This only increases Z, A, D, E visits by 1

Upvotes: 1

Lorena Gil
Lorena Gil

Reputation: 351

Here is a posible solution:

df.visit[df.visit == 0] += 1

Upvotes: 1

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