human
Give me a Python program for filling null value sin data frame.
assistant
Here is a Python program for filling null value sin data frame

import pandas as pd

def fill_null_value(df):
    """Fill null value sin data frame in """
    df.fillna(value=0, inplace=True)
    return df

# Enter the dataframe
df = pd.DataFrame({"a": [1, 2, 3, 4, 5], "b": [1, 2, 3, 4, 5]})

# Calling the function
df = fill_null_value(df)

# Printing the dataframe
print(df)

#Example Output

#    a  b
# 0  1  1
# 1  2  2
# 2  3  3
# 3  4  4
# 4  5  5

#Remember to inspect code for bugs.