python sum a column's value with condition

Question

I have the below dataframe. I would like to return a second column that is the sum of every item in the column with a condition: only those larger than -1.

input

output

   Price     Total Sum
0    12          88
1    14
2    15
3    10
4     2
5     4
6    -5
7    -4
8    -3
9    -5
10   16
11   15

Please always provide a reproducible example : pytohn code of the values at least — azro
– azro, Commented Nov 28, 2021 at 11:58
df["Positive"] = max(df["Price"], 0) then result = df["Positive"].sum() — Larry the Llama
– Larry the Llama, Commented Nov 28, 2021 at 11:58

azro · Accepted Answer · 2021-11-28 12:01:36Z

3

To get the sum of positive values in the column, use the appropriate condition

import pandas as pd

df = pd.DataFrame({'price': [12, 14, 15, 10, 2, 4, -5, -4, -3, -5, 16, 15]})
total = df.loc[df['price'] > 0, 'price'].sum()
print(total)  # 88

That isn't a good idea to set a column with values not relative to the other row param, here one single value. But to get the logic

# you need to pad with zeros, if you not you'll have 88 at every row
df['total'] = [total] + [0] * (len(df) - 1)
print(df)

    price  total
0      12     88
1      14      0
2      15      0
3      10      0
4       2      0
5       4      0
6      -5      0
7      -4      0
8      -3      0
9      -5      0
10     16      0
11     15      0

answered Nov 28, 2021 at 12:01

azro

54.2k9 gold badges39 silver badges75 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

tdy Over a year ago

+10, but instead of making a manual list, could create the column like this: df.loc[0, 'total'] = total

Wyrden · Accepted Answer · 2021-11-28 12:13:00Z

0

I would not recommend making another column with only one value in it. To get the sum of all prices you could do:

all_prices = []
df = pandas.read_csv("prices.csv")
df_price = df["price"]
print(df_price.sum())

edited Nov 28, 2021 at 12:13

answered Nov 28, 2021 at 12:07

Wyrden

456 bronze badges

Collectives™ on Stack Overflow

python sum a column's value with condition

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related