擅长:python、mysql、java
<p>我将<a href="https://docs.scipy.org/doc/numpy-1.15.0/reference/generated/numpy.select.html" rel="nofollow noreferrer">np.select</a>与多个条件一起使用:</p>
<pre><code>conditions = [
country['POPULATION'] < 2000,
((country['POPULATION'] > 2000) & (country['POPULATION'] <= 4000)),
((country['POPULATION'] > 5000) & (country['POPULATION'] <=6000))
]
choices = [
'small',
'medium',
'big'
]
# create a new column or assign it to an existing
# the last param in np.select is default
country['new'] = np.select(conditions, choices, 'huge')
COUNTRY POPULATION ECONOMY new
0 China 1200 86212 small
1 JAPAN 2345 11862 medium
2 KOREA 3400 1000 medium
3 USA 5600 8555 big
4 UK 9600 12000 huge
</code></pre>