code: def is_dataframe(obj):
      """
      Returns True if the given object is a Pandas Data Frame.
  
      Parameters
      ----------
      obj: instance
          The object to test whether or not is a Pandas DataFrame.
      """
      try:
          # This is the best method of type checking
          from pandas import DataFrame
  
          return isinstance(obj, DataFrame)
      except ImportError:
          # Pandas is not a dependency, so this is scary
          return obj.__class__.__name__ == "DataFrame"
  
file_path: yellowbrick/yellowbrick/utils/types.py
imports: import inspect
  import numpy
  from sklearn.base import BaseEstimator
  from yellowbrick.contrib.wrapper import ContribEstimator
label_desc: Use image node_id 7 for calling a global function with example usage: is_dataframe(obj) and returns: isinstance, unknown