pandas read csv returns dataframe as object type

Question

While reading csv file df = pd.read_csv('lightcurve.csv',header=None) and creating the dataframe, my datatypes is in objects. How can I read my csv so that I can do df.dropna to remove all NULL values. There is also NULL values in my csv. Any suggestions would be great help.

The image of my data in csv file is : enter image description here

Answer 1

Based on the information provided I feel this is how your data looks like.

import numpy as np
import pandas as pd
from io import StringIO

inp = StringIO("""1,22.3,53,5.5
23,34.5,5,7.2
43,n,n,n""")

df = pd.read_csv(inp,header=None)

print(df)

df = df.replace('n',np.nan).dropna()

print(df)