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.

First Steps

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