[Python] Problem when try to filter column in pandas [duplicate]

In this example, I'm filtering some values.

df = pd.DataFrame([{'A': -23.972176, 'B': -51.408777, 'C': np.NaN}, {'A': -23.972176, 'B': -49.959970, 'C': np.NaN}, {'A': -23.972176, 'B': -46.310840, 'C': 46.541667}])
df[df['B']==-46.310840]


When I did this, it returned the last row, as it should be.

But, I'm working in a data frame with 591624 rows × 4 columns. The columns are Date, Latitude, Longitude, and Values.



I want to filter the specific latitude and longitude.

df[df['lat']==-23.972176]


But, when I try to filter a particular latitude, it returns nothing. This specific latitude should appear more than 1800 times. I know that this latitude is in the DataFrame.

What could be happening?

The Latitude, Longitude, and MP10 are float64, and time is datetime64[ns].

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