Pandas update with condition

import pandas as pd
import numpy as np

df = pd.DataFrame({'value':np.arange(1000000)})

# Solution 1 - Fastest :
df['value'] = np.where(df['value'] > 20000, 0, df['value'])

# Solution 2:
df.loc[df['value'] > 20000, 'value'] = 0

# Solution 3:
df['value'] = df['value'].mask(df['value'] > 20000, 0)

# Solution 4 - Slowest, note that df.where applies where condition is wrong:
df['a'] = df.where(df.a <= 20000, 0)

Pandas filter and change value

df.loc[df['dollars_spent'] > 0, 'purchase'] = 1

Similar codes

0 vote214 views1 answer
Python .exe long start
Python
-2 votes208 views1 answer
Center buttons tkinter
Python
2 votes200 views1 answer
List comprehension python 3 hackerrank solution
Python
125 votes227 views6 answers
Dataframe rename column
Python
7 votes205 views5 answers
Unnamed 0 pandas
Python
0 vote202 views1 answer
How to count a consecutive series of positive or negative values in a column in python
Python
11 votes218 views3 answers
Django q filter
Python
10 votes235 views1 answer
Pandas dataframe creation column names
Python
40 votes215 views6 answers
How to print error in try except python
Python
0 vote222 views1 answer
Reset all weights keras
Python