Summary  
This chapter introduces printing in Python code using the built-in print function to display text and data.  

General domain of usage  
data analysis

import unittest
import re
from io import StringIO
from contextlib import redirect_stdout
import importlib

def _dynamic_test(test_case, condition, success_message, failure_message):
    if condition:
        test_case._testMethodName = success_message
        test_case.assertTrue(True, success_message)
    else:
        test_case._testMethodName = failure_message
        test_case.fail(failure_message)

class TestUserCode(unittest.TestCase):

    def test_first_print_outputs_greeting(self):
        # Capture the output of the user code execution.
        import user_code  # The user's solution file should be named "user_code.py".
        f = StringIO()
        with redirect_stdout(f):
            importlib.reload(user_code)
        output = f.getvalue().strip()
        lines = output.splitlines()

        condition = (len(lines) >= 1 and
                     lines[0].strip().lower() == "welcome to the grocery".lower())
        _dynamic_test(
            self,
            condition,
            "The first print line correctly outputs 'Welcome to the Grocery'.",
            "Expected the first line to print 'Welcome to the Grocery' (case insensitive) but got: '{}'".format(
                lines[0] if len(lines) >= 1 else ""
            )
        )

    def test_second_print_outputs_store(self):
        # Capture the output of the user code execution.
        import user_code  # The user's solution file should be named "user_code.py".
        f = StringIO()
        with redirect_stdout(f):
            importlib.reload(user_code)
        output = f.getvalue().strip()
        lines = output.splitlines()

        condition = (len(lines) >= 2 and
                     lines[1].strip().lower() == "store".lower())
        _dynamic_test(
            self,
            condition,
            "The second print line correctly outputs 'Store'.",
            "Expected the second line to print 'Store' (case insensitive) but got: '{}'".format(
                lines[1] if len(lines) >= 2 else ""
            )
        )

if __name__ == '__main__':
    unittest.main()


test_main.py

Gain a solid foundation in Python for data analysis. Learn to work with variables, data types, strings, conditional statements, loops, core data structures, and functions using examples relevant to analytical tasks.

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