human
list out all column names.
assistant
Here is a Python code to return list out all column names

import pandas as pd

def list_columns(df):
  """Return a list of column names."""
  return df.columns.tolist()

# Create a dataframe
df = pd.DataFrame({'age': [1, 2, 3], 'name': ['rose','skateboard','mouse']})

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

#Example Output
# ['age', 'name']

#Remember to inspect code for bugs.