擅长:python、mysql、java
<p>您可以在<code>Grades</code>和<a href="http://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.Series.map.html" rel="nofollow noreferrer">^{<cd2>}</a>中创建所有可能值的字典:</p>
<pre><code>#test all possible unique values
print (df['Grades'].unique())
d = {'91 50K':'Petrol','92 60K':'Petrol','DIESEL':'Diesel',...}
df['Grades'] = df['Grades'].map(d)
</code></pre>
<p>另一个可能减少键入的字典是dict of list:</p>
<pre><code>d1 = {'Petrol':['91 50K','92 60K'],
'Diesel':['DIESEL']}
#swap key values in dict
#http://stackoverflow.com/a/31674731/2901002
d = {k: oldk for oldk, oldv in d1.items() for k in oldv}
print (d)
{'91 50K': 'Petrol', '92 60K': 'Petrol', 'DIESEL': 'Diesel'}
df['Grades'] = df['Grades'].map(d)
</code></pre>