human
What is a good Python code to determine if a data frame has a null value.
assistant
Here is a Python code to determine if a data frame has a null value

import pandas as pd

def _has_null(df):
  """Helper that returns if data frame has a null."""
  return df.isnull().values.any()

# Enter the dataframe
df = pd.DataFrame({'a': [1, 2, 3], 'b': [4, 5, 6]})

# Calling the function
print((_has_null(df)))

#Example Output
# False

#Remember to inspect code for bugs.