I have the following data frames: df3
| Harvest_date | Starting_date | 
|---|---|
| 2022-10-06 | 2022-08-06 | 
| 2022-02-22 | 2021-12-22 | 
df (I have all temp and humid starting from 2021-01-01 till the present)
| date | temp | humid | 
|---|---|---|
| 2022-10-06 00:30:00 | 2 | 30 | 
| 2022-10-06 00:01:00 | 1 | 30 | 
| 2022-10-06 00:01:30 | 0 | 30 | 
| 2022-10-06 00:02:00 | 0 | 30 | 
| 2022-10-06 00:02:30 | -2 | 30 | 
I would like to calculate the avg temperature and humidity between the starting_date and harvest_date. I tried this:
import pandas as pd
df = pd.read_csv (r'C:climate.csv')
df3 = pd.read_csv (r'C:Flower_weight_Seson.csv')
df['date'] = pd.to_datetime(df.date)
df3['Harvest_date'] = pd.to_datetime(df3.Harvest_date)
df3['Starting_date'] = pd.to_datetime(df3.Starting_date)
df.style.format({"date": lambda t: t.strftime("%Y-%m-%d")})
df3.style.format({"Harvest_date": lambda t: t.strftime("%Y-%m-%d")})
df3.style.format({"Starting_date": lambda t: t.strftime("%Y-%m-%d")})
for harvest_date,starting_date in zip(df3['Harvest_date'],df3['Starting_date']):
    df3["Season avg temp"]= df[df["date"].between(starting_date,harvest_date)]["temp"].mean()
    df3["Season avg humid"]= df[df["date"].between(starting_date,harvest_date)]["humid"].mean()
I get the same value for all dates. Can someone point out what I did wrong, please?
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Answer
Use DataFrame.loc with match indices by means of another DataFrame:
#changed data for match with df3
print (df)
                  date  temp  humid
0  2022-10-06 00:30:00     2     30
1  2022-09-06 00:01:00     1     33
2  2022-09-06 00:01:30     0     23
3  2022-10-06 00:02:00     0     30
4  2022-01-06 00:02:30    -2     25
for i,harvest_date,starting_date in zip(df3.index,df3['Harvest_date'],df3['Starting_date']):
    mask = df["date"].between(starting_date,harvest_date)
    avg = df.loc[mask, ["temp",'humid']].mean()
    df3.loc[i, ["Season avg temp",'Season avg humid']] = avg.to_numpy()
print (df3)
  Harvest_date Starting_date  Season avg temp  Season avg humid
0   2022-10-06    2022-08-06              0.5              28.0
1   2022-02-22   2021-12-220             -2.0              25.0
EDIT: For add new condition for match by room columns use:
for i,harvest_date,starting_date, room in zip(df3.index,
                                              df3['Harvest_date'],
                                              df3['Starting_date'], df3['Room']):
    mask = df["date"].between(starting_date,harvest_date) & df['Room'].eq(room)
    avg = df.loc[mask, ["temp",'humid']].mean()
    df3.loc[i, ["Season avg temp",'Season avg humid']] = avg.to_numpy()
print (df3)
