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 vote130 views1 answer
Python pass command is 'Do Nothing'
Python
2 votes129 views1 answer
Matplotlib multiple plots with different size
Python
1 vote132 views1 answer
How to ask someone for their name in python
Python
1 vote122 views3 answers
Char list to string python
Python
5 votes121 views2 answers
2d list comprehension python
Python
0 vote129 views1 answer
Colorama input python
Python
3 votes81 views3 answers
Add items to list in python 3
Python
6 votes124 views4 answers
Python convert 12 hour time to 24 hour
Python
9 votes123 views1 answer
Print current dirfile dir python
Python
1 vote133 views1 answer
If none in column remove row
Python