Modifying a subset of rows in a pandas DataFrame Now, we will use theloc[]property for modifying a column value, suppose we want a value to be set for a column whenever a certain condition is met for another column, we can use the following concept: df.loc[selection criteria, columns I...
Random Sample of a subset of a dataframeFor this purpose, we will use pandas.DataFrame.sample() method. It is used to return a random sample of items from an object.Syntax:DataFrame.sample( n=None, frac=None, replace=False, weights=None, random_state=None, axis=None, ignore_index=False...
When doing a subselection of columns on a DataFrameGroupBy object, both a plain list (so a tuple within the__getitem__[] brackets) as the double square brackets (a list inside the__getitem__[] brackets) seems to work: In [6]: df = pd.DataFrame(np.random.randint(10, size=(10, 4...