fillna.py

import pandas as pd

data = pd.read_csv('test.csv')
# array3 = data['Column2'].replace(np.NaN,-1)
# length = array3.shape[0]
# print(length)
# arr3 = [];
# for i in range(length):
#     if array3[i] != -1:
# #         print(i)
#         arr3.append(array[i])  
# 
# print(arr3)
# trimmed = st.trim_mean(arr3,.05)
# mask=(data['Column1']=='Yes') & ((data['Column2'=='NA']) |(data['Column2'=='No'])
# data.loc[mask,'Column2']=pd.to_numeric(data['Column2'],errors='coerce').fillna(trimmed)

data['Column2'] = data['Column2'].fillna(data.apply(lambda cols: round(data['Column2'].mean(),2) if cols[0]=='yes' else -1, axis=1))
data.to_csv(r'data.csv', index=False)

@PP227 have a look. I added here the solution with two sample output.

from scipy import stats as st
from sklearn.utils import shuffle
import numpy as np
import pandas as pd

data = pd.read_csv('training.csv')
data['Diabetes_medicine_years'] = data['Diabetes_medicine_years'].replace('VALID', np.NaN)
data['Diabetes_medicine_years'] = data.Diabetes_medicine_years.astype(float)
array3 = data['Diabetes_medicine_years'].replace(np.NaN,-1)
length = array3.shape[0]
# print(length)
arr3 = [];
for i in range(length):
    if array3[i] != -1:
        arr3.append(array3[i])  

# print(arr3)
trimmed = st.trim_mean(arr3, .05)
# mask=(data['Diabetes']=='Yes') & ((data['Diabetes_medicine_years'=='NA']) |(data['Diabetes_medicine_years'=='No']|(data['Diabetes_medicine_years'=='VALID'])))
# data.loc[mask,'Diabetes_medicine_years']=pd.to_numeric(data['Diabetes_medicine_years'],errors='coerce').fillna(16.52)
# # data.to_csv(r'data.csv')
# data.head(5)

# if Diabetes == 'yes and Diabetes_medicine_years == 'no' or 'na' else "Diabetes_medicine_years"'s value will insert into Diabetes_medicine_years field
data['Diabetes_medicine_years'] = data['Diabetes_medicine_years'].fillna(data.apply(lambda cols: trimmed if str(cols.Diabetes).lower() == 'yes' and (str(cols.Diabetes_medicine_years).lower() == 'nan' or str(cols.Diabetes_medicine_years).lower() == 'no') else cols.Diabetes_medicine_years, axis=1))
# if diabetes not equal 'yes' and you may want to add empty string into 'Diabetes_medicine_years' then you may uncomment this line.
# data['Diabetes_medicine_years'] = data['Diabetes_medicine_years'].fillna(data.apply(lambda cols: trimmed if str(cols.Diabetes).lower() == 'yes' and (str(cols.Diabetes_medicine_years).lower() == 'nan' or str(cols.Diabetes_medicine_years).lower() == 'no') else '', axis=1))
data.to_csv('data.csv', index=False)
data

Sample Output 1

	Hypertension	Hypertension_medicine_years	Diabetes	Diabetes_medicine_years
0	Yes	1	No	NaN
1	Yes	6	Yes	13.00
2	Yes	VALID	No	NaN
3	NaN	NaN	NaN	NaN
4	Yes	2	No	NaN
5	Yes	6	No	NaN
6	Yes	14	Yes	14.00
7	Yes	5	No	NaN
8	Yes	0.5	Yes	2.00
9	No	NaN	No	NaN
10	Yes	VALID	Yes	3.00
11	No	NaN	No	NaN
12	No	NaN	No	NaN
13	Yes	VALID	No	NaN
14	No	NaN	No	NaN
15	Yes	2	No	NaN
16	No	NaN	No	NaN
17	No	NaN	No	NaN
18	Yes	VALID	Yes	7.00
19	Yes	VALID	Yes	5.95
20	No	NaN	Yes	7.00
21	No	NaN	No	NaN
22	Yes	4	No	NaN
23	No	NaN	Yes	3.00
24	No	NaN	No	NaN
25	Yes	2	Yes	5.95
26	Yes	5	No	NaN
27	Yes	3	Yes	2.00
28	Yes	10	No	NaN
29	Yes	2	Yes	8.00
30	Yes	0.5	Yes	0.50
31	No	NaN	No	NaN
32	Yes	10	No	NaN
33	No	NaN	No	NaN

from scipy import stats as st
from sklearn.utils import shuffle
import numpy as np
import pandas as pd

data = pd.read_csv('training.csv')
data['Diabetes_medicine_years'] = data['Diabetes_medicine_years'].replace('VALID', np.NaN)
data['Diabetes_medicine_years'] = data.Diabetes_medicine_years.astype(float)
array3 = data['Diabetes_medicine_years'].replace(np.NaN,-1)
length = array3.shape[0]
# print(length)
arr3 = [];
for i in range(length):
    if array3[i] != -1:
        arr3.append(array3[i])  

# print(arr3)
trimmed = st.trim_mean(arr3, .05)
# mask=(data['Diabetes']=='Yes') & ((data['Diabetes_medicine_years'=='NA']) |(data['Diabetes_medicine_years'=='No']|(data['Diabetes_medicine_years'=='VALID'])))
# data.loc[mask,'Diabetes_medicine_years']=pd.to_numeric(data['Diabetes_medicine_years'],errors='coerce').fillna(16.52)
# # data.to_csv(r'data.csv')
# data.head(5)

# if Diabetes == 'yes and Diabetes_medicine_years == 'no' or 'na' else "Diabetes_medicine_years"'s value will insert into Diabetes_medicine_years field
# data['Diabetes_medicine_years'] = data['Diabetes_medicine_years'].fillna(data.apply(lambda cols: trimmed if str(cols.Diabetes).lower() == 'yes' and (str(cols.Diabetes_medicine_years).lower() == 'nan' or str(cols.Diabetes_medicine_years).lower() == 'no') else cols.Diabetes_medicine_years, axis=1))
# if diabetes not equal 'yes' and you may want to add empty string into 'Diabetes_medicine_years' then you may uncomment this line.
data['Diabetes_medicine_years'] = data['Diabetes_medicine_years'].fillna(data.apply(lambda cols: trimmed if str(cols.Diabetes).lower() == 'yes' and (str(cols.Diabetes_medicine_years).lower() == 'nan' or str(cols.Diabetes_medicine_years).lower() == 'no') else '', axis=1))
data.to_csv('data.csv', index=False)
data

Sample Output 2

	Hypertension	Hypertension_medicine_years	Diabetes	Diabetes_medicine_years
0	Yes	1	No
1	Yes	6	Yes	13
2	Yes	VALID	No
3	NaN	NaN	NaN
4	Yes	2	No
5	Yes	6	No
6	Yes	14	Yes	14
7	Yes	5	No
8	Yes	0.5	Yes	2
9	No	NaN	No
10	Yes	VALID	Yes	3
11	No	NaN	No
12	No	NaN	No
13	Yes	VALID	No
14	No	NaN	No
15	Yes	2	No
16	No	NaN	No
17	No	NaN	No
18	Yes	VALID	Yes	7
19	Yes	VALID	Yes	5.95
20	No	NaN	Yes	7
21	No	NaN	No
22	Yes	4	No
23	No	NaN	Yes	3
24	No	NaN	No
25	Yes	2	Yes	5.95
26	Yes	5	No
27	Yes	3	Yes	2
28	Yes	10	No
29	Yes	2	Yes	8
30	Yes	0.5	Yes	0.5
31	No	NaN	No
32	Yes	10	No
33	No	NaN	No