df.query('ZIP_(3-DIGIT) < 100')
returns:
ValueError: "ZIP_" is not a supported function
df.query('@ZIP_(3-DIGIT) < 100')
returns:
ValueError: "__pd_eval_local_ZIP_" is not a supported function
ZIP_(3-DIGIT) is int64
I can use df[df['ZIP_(3-DIGIT)'] < 100] to achieve the desired result, but I would like to learn what I was doing wrong.
df = pd.DataFrame({'ZIP_(3-DIGIT)': np.arange(0,10000)})
The issue is with the parentheses and hyphen in your column name.
Any column that you couldn't access with df + tab also can't be parsed by .query. I don't know pandas internals and can't answer your question beyond that level of depth.
For example if you had:
df = pd.DataFrame({'ZIP_3DIGIT': np.arange(0,10000)})
You could do:
print(df.ZIP_3DIGIT.head(3))
0 0
1 1
2 2
Name: ZIP_3DIGIT, dtype: int32
Now try this with your current name and things will not work.
So to use query, use rename and method chain query to that:
df.rename(columns={'ZIP_(3-DIGIT)' : 'ZIP_3DIGIT'}).query('ZIP_3DIGIT < 100')
