class Pipeline(object):

The `Pipeline` class is a way to combine multiple steps of a machine learning workflow into a single object. It is commonly used in natural language processing tasks, such as text classification.

The `Pipeline` class takes a list of tuples as an argument, where each tuple represents a step in the workflow. The first element of the tuple is the name of the step, and the second element is an instance of a transformer or estimator class. The output of each step is passed as input to the next step in the pipeline.

For example, a simple text classification pipeline could consist of the following steps:
1. Tokenization
2. Vectorization
3. Classification

The `Pipeline` class can be used to combine these steps into a single object, which can then be fit to training data and used to make predictions on new data.