Python Pandas：按条件累积数据框行

Question

I have a data frame with 2 columns in following format:

Anna         15
Mary         14
Elizabeth    11
Margaret     10
Alice         6
Bertha        5
Helen         5
Emily         4
Maria         4
Marie         4
Catherine     4
Marion        4
Ellen         4
Florence      4
Augusta       4
...
Juliette      1
Mara          1
Elise         1
Alfrida       1
Nourelain     1
Margaretta    1
Manca         1
Aloisia       1
Hulda         1
Clear         1
Wendla        1
Ellis         1
Lulu          1
Juliet        1
Gertrude      1

How can I accumulate rows with value < 5 to get something like

Anna 15 Mary 14 Elizabeth 11 Margaret 10 Alice 6 Bertha 5 Helen 5 Other 50

Answer 1

here is a way:

# create some random data
df =pd.DataFrame({'letter': list('qwertyuiopasdfghjklzxcvbnm'),'value': np.random.randint(1,15,26)})

define a function to replace letters where value < 5 with other:

def f(x):
    if x.value <5:
        l= 'other'
    else:
        l =x.letter
    return l

apply the function to the dataframe:

df['letter'] =df.apply(f,axis=1)

group by the new letter column and sum:

df.groupby('letter').sum()