Opening files

301.15 File Handling Techniques

File Handling Techniques — Note 1 of 4

Open read write append.

What you need to know

Use open() with a mode to access a file. Common modes are "r" (read), "w" (write — overwrites), and "a" (append — adds to end). The with statement auto-closes the file.

What to know

"r" = read (default), "w" = write, "a" = append
"w" overwrites the entire file — data is lost!
"a" adds to the end without deleting existing content
with open() as f: auto-closes when done

Code examples

Opening files

python

# Read mode
with open("data.txt", "r") as f:
    contents = f.read()

# Write mode (overwrites)
with open("output.txt", "w") as f:
    f.write("Hello")

# Append mode (adds to end)
with open("log.txt", "a") as f:
    f.write("New entry\n")

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Specification notes for programming are in Paper 2.

Opening files

301.15 File Handling Techniques

Practise exam questions

File Handling Techniques — Note 1 of 4

Open read write append.

What you need to know

Use open() with a mode to access a file. Common modes are "r" (read), "w" (write — overwrites), and "a" (append — adds to end). The with statement auto-closes the file.

What to know

"r" = read (default), "w" = write, "a" = append
"w" overwrites the entire file — data is lost!
"a" adds to the end without deleting existing content
with open() as f: auto-closes when done

Code examples

Opening files

python

# Read mode
with open("data.txt", "r") as f:
    contents = f.read()

# Write mode (overwrites)
with open("output.txt", "w") as f:
    f.write("Hello")

# Append mode (adds to end)
with open("log.txt", "a") as f:
    f.write("New entry\n")

← Previous topicOff-by-one301.14 Random Number Generation Next note →Reading files301.15 File Handling Techniques

Back to File Handling Techniques

Specification notes for programming are in Paper 2.