text: """Package0 - a collection of Data Science helpfer functions"""
  import pandas as pd
  
  
  def data_null_check(df):
      """Prints out nulls of dataframe into a nice data frame format"""
      if type(df) == pd.core.frame.DataFrame:
          return df.isnull().sum()
  
  
  def features_select(df, name_target, max_cardinality=20):
      """creates features, and target from data frame, takes dataframe, name of
      feature in strings, and has an optional 3rd parameter of max cardinality allowed"""
      target = name_target
      # creating subsets of features, split between numerical and categorical
      train_features = df.drop(columns=[name_target], axis=1)
      numeric_features = train_features.select_dtypes(include='number').columns.tolist()
      cardinality = train_features.select_dtypes(exclude='number').nunique()
      categorical_features = cardinality[cardinality <= max_cardinality].index.tolist()
      # combine lists to extrapolate features of interest
      features = numeric_features + categorical_features
      return features, target
  