Handling multiple resources in Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of nested with statements

What is the output of this Python code that opens two files using nested with statements?

Python

with open('file1.txt', 'w') as f1:
    f1.write('Hello')
with open('file2.txt', 'w') as f2:
    f2.write('World')

with open('file1.txt', 'r') as f1:
    with open('file2.txt', 'r') as f2:
        print(f1.read() + ' ' + f2.read())

A SyntaxError

B HelloWorld

C Hello World

D World Hello

💡 Hint

Remember that the files are opened and read in the order of the nested with statements.

The code writes 'Hello' to file1.txt and 'World' to file2.txt. Then it opens file1.txt and file2.txt for reading in nested with statements and prints their contents separated by a space, resulting in 'Hello World'.

❓ Predict Output

intermediate

Using multiple context managers in one with statement

What will this code print when opening two files in a single with statement?

Python

with open('file1.txt', 'w') as f1, open('file2.txt', 'w') as f2:
    f1.write('Data1')
    f2.write('Data2')

with open('file1.txt', 'r') as f1, open('file2.txt', 'r') as f2:
    print(f1.read() + '-' + f2.read())

A TypeError

B Data1-Data2

C Data1Data2

D Data2-Data1

💡 Hint

Multiple context managers can be opened in one with statement separated by commas.

Both files are opened simultaneously in one with statement. The contents are read and joined with a dash, printing 'Data1-Data2'.

🔧 Debug

advanced

Identify the error in resource handling

What error does this code raise when trying to open two files using nested with statements incorrectly?

Python

with open('file1.txt', 'r') as f1:
    with open('file2.txt', 'r') as f2:
        print(f1.read() + f2.read())

A TypeError

B FileNotFoundError

C IndentationError

D SyntaxError

💡 Hint

Check the syntax of the with statement lines carefully.

The second with statement is missing a colon at the end, causing a SyntaxError.

❓ Predict Output

advanced

Effect of exception inside multiple with statement

What will be printed by this code that opens two files and raises an exception inside the with block?

Python

try:
    with open('file1.txt', 'w') as f1, open('file2.txt', 'w') as f2:
        f1.write('Test')
        raise ValueError('Oops')
        f2.write('Fail')
except ValueError as e:
    print('Caught:', e)

with open('file1.txt', 'r') as f1:
    print(f1.read())

A

Caught: Oops
Test

B

Caught: Oops

C

Test
Caught: Oops

D Test

💡 Hint

The exception stops execution inside the with block but the file is still written and closed properly.

The exception is caught and printed. The first file was written before the exception, so reading it prints 'Test'.

🧠 Conceptual

expert

Order of resource release in multiple context managers

When using multiple context managers in one with statement like with A() as a, B() as b:, in which order are the resources released (their __exit__ methods called)?

A First B's __exit__ then A's __exit__

B First A's __exit__ then B's __exit__

C Both __exit__ methods are called simultaneously

D Order is undefined and depends on Python version

💡 Hint

Think about how nested with statements work and the stack of context managers.

Python calls __exit__ methods in reverse order of __enter__ calls. So B's __exit__ is called before A's __exit__.