Opening and closing files in Python - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to open a file named 'data.txt' for reading.

Python

file = open('data.txt', '[1]')

Drag options to blanks, or click blank then click option'

Ax

Br

Ca

Dw

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'w' which overwrites the file instead of reading.

Using 'a' which appends to the file instead of reading.

The mode 'r' opens the file for reading only.

2fill in blank

medium

Complete the code to close the file object named 'file'.

Python

file.[1]()

Drag options to blanks, or click blank then click option'

Aopen

Bread

Cclose

Dwrite

Attempts:

3 left

💡 Hint

Common Mistakes

Calling open() again instead of closing.

Forgetting to close the file causing resource leaks.

The close() method closes the file and frees resources.

3fill in blank

hard

Fix the error in the code to properly open a file for writing.

Python

file = open('output.txt', '[1]')

Drag options to blanks, or click blank then click option'

Arb

Br

Ca

Dw

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'r' mode which is for reading only.

Using 'rb' which is for reading binary files.

The mode 'w' opens the file for writing, creating it if it doesn't exist.

4fill in blank

hard

Fill both blanks to open a file for appending and then close it.

Python

file = open('log.txt', '[1]')
file.[2]()

Drag options to blanks, or click blank then click option'

Aa

Bclose

Cread

Dw

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'w' instead of 'a' which overwrites the file.

Forgetting to close the file.

Use 'a' to open the file for appending and close() to close it.

5fill in blank

hard

Fill all three blanks to open a file for reading, read its content, and then close it.

Python

file = open('notes.txt', '[1]')
content = file.[2]()
file.[3]()

Drag options to blanks, or click blank then click option'

Ar

Bread

Cclose

Dw

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'w' mode which is for writing.

Forgetting to close the file after reading.

Open with 'r' for reading, use read() to get content, then close() the file.

Practice

1. What does the open() function do in Python when working with files?

easy

A. It opens a file and returns a file object to work with the file.

B. It closes a file that is currently open.

C. It deletes a file from the system.

D. It reads the entire content of a file automatically.

Solution

1. Step 1: Understand the purpose of open()

   The open() function is used to open a file and create a file object that allows reading, writing, or other operations.

2. Step 2: Differentiate from other file operations

   Closing a file is done with close(), deleting is done with other functions, and reading content requires calling methods on the file object.

3. Final Answer:

   It opens a file and returns a file object to work with the file. -> Option A

4. Quick Check:

   open() opens file [OK]

Hint: Remember: open() creates file object, close() ends it [OK]

Common Mistakes:

• Confusing open() with close()
• Thinking open() reads file content automatically
• Assuming open() deletes files

2. Which of the following is the correct syntax to open a file named data.txt for reading in Python?

easy

A. file = open('data.txt', 'w')

B. file = open('data.txt', 'r')

C. file = open('data.txt', 'x')

D. file = open('data.txt', 'a')

Solution

1. Step 1: Identify the mode for reading

   The mode 'r' stands for reading a file, which is the correct mode to open a file for reading.

2. Step 2: Check other modes

   'w' is for writing (overwrites), 'x' is for creating a new file, 'a' is for appending to a file.

3. Final Answer:

   file = open('data.txt', 'r') -> Option B

4. Quick Check:

   Mode 'r' means read [OK]

Hint: Use 'r' mode to open files for reading [OK]

Common Mistakes:

• Using 'w' mode which overwrites file
• Using 'x' mode which fails if file exists
• Using 'a' mode which appends instead of reading

3. What will be the output of the following code?

file = open('example.txt', 'w')
file.write('Hello')
file.close()
file = open('example.txt', 'r')
print(file.read())
file.close()

medium

A. '' (empty string)

B. example.txt

C. Hello

D. Error: file not found

Solution

1. Step 1: Write 'Hello' to the file

   The file is opened in write mode, 'Hello' is written, then the file is closed to save changes.

2. Step 2: Read the content back

   The file is reopened in read mode, and read() returns the string 'Hello' which is printed.

3. Final Answer:

   Hello -> Option C

4. Quick Check:

   Write then read returns written text [OK]

Hint: Write then close before reading to see content [OK]

Common Mistakes:

• Not closing file before reading
• Expecting filename as output
• Assuming empty string without write

4. Identify the error in the following code snippet:

file = open('notes.txt', 'r')
content = file.read()
print(content)
file.write('More notes')
file.close()

medium

A. Trying to write to a file opened in read mode causes an error.

B. The file is not closed before reading.

C. The print statement is incorrect syntax.

D. The file name should be in double quotes.

Solution

1. Step 1: Check file mode and operations

   The file is opened in 'r' (read) mode, which does not allow writing.

2. Step 2: Identify the invalid operation

   Calling file.write() on a file opened for reading causes a runtime error.

3. Final Answer:

   Trying to write to a file opened in read mode causes an error. -> Option A

4. Quick Check:

   Write not allowed in 'r' mode [OK]

Hint: Write only in 'w' or 'a' modes, not 'r' [OK]

Common Mistakes:

• Trying to write in read mode
• Ignoring file close after reading
• Thinking quotes style matters for filename

5. You want to safely read a file named log.txt and automatically close it after reading. Which code snippet correctly does this using Python's best practice?

hard

A. file = open('log.txt', 'r')
content = file.read()
file.close()

B. open('log.txt', 'r').read()

C. file = open('log.txt', 'r')
content = file.read()

D. with open('log.txt', 'r') as file:
content = file.read()

Solution

1. Step 1: Understand safe file handling

   Using with statement ensures the file is automatically closed after the block finishes, even if errors occur.

2. Step 2: Compare options

   file = open('log.txt', 'r') content = file.read() file.close() requires manual close, C misses close, D reads but does not save content or close explicitly.

3. Final Answer:

   with open('log.txt', 'r') as file: content = file.read() -> Option D

4. Quick Check:

   Use with statement for auto-close [OK]

Hint: Use with open(...) as file for automatic closing [OK]

Common Mistakes:

• Forgetting to close file manually
• Not using with statement for safety
• Ignoring file object after open()