Read Files

Read file content directly from the sandbox as a string.

sandbox.read_file(
    path: str,
    encoding: str = "utf-8"
) -> str

4MB Limit: Maximum file size is 4MB. For larger files, use download_file().

Parameters

pathstringrequired

Absolute path in the sandbox to read from. Must start with /.

encodingstring

Text encoding for decoding file content. Default: "utf-8"

Returns

string

The content of the file as a decoded string.

When to Use read_file vs download_file

Feature	read_file()	download_file()
Size Limit	4MB	Unlimited (streaming)
Return Type	String (in memory)	Boolean (saves to file)
Use Case	Quick reads, text files, configs	Large files, binary files, archives
Progress Tracking	No	Yes (callback)
Checksum Verification	No	Yes (optional)

Basic Usage

from concave import sandbox

with sandbox() as sbx:
    # Read a text file
    content = sbx.read_file("/tmp/data.txt")
    print(content)
    
    # Read a JSON file
    import json
    json_content = sbx.read_file("/tmp/config.json")
    config = json.loads(json_content)
    print(config)

Advanced Examples

Reading with Different Encodings

# Read a file with latin-1 encoding
content = sbx.read_file("/tmp/legacy.txt", encoding="latin-1")

# Read an ASCII file
content = sbx.read_file("/tmp/ascii.txt", encoding="ascii")

Processing File Content

# Read and process a CSV file
csv_content = sbx.read_file("/tmp/data.csv")
lines = csv_content.strip().split("\n")
for line in lines:
    columns = line.split(",")
    print(columns)

# Read and parse YAML
import yaml
yaml_content = sbx.read_file("/tmp/config.yaml")
config = yaml.safe_load(yaml_content)

Reading Code Files

# Read Python code
script = sbx.read_file("/tmp/script.py")
print("Script contents:")
print(script)

# Execute the script after reading
result = sbx.run(script)
print(result.stdout)

Error Handling

from concave import (
    sandbox,
    SandboxFileNotFoundError,
    SandboxValidationError,
    SandboxPermissionDeniedError
)

with sandbox() as sbx:
    try:
        content = sbx.read_file("/tmp/data.txt")
        print(content)
    except SandboxFileNotFoundError as e:
        print(f"File not found: {e.path}")
    except SandboxValidationError as e:
        print(f"Validation error: {e}")
    except SandboxPermissionDeniedError as e:
        print(f"Permission denied: {e.path}")

Exceptions

SandboxFileNotFoundError

Raised when the specified file doesn't exist in the sandbox.

SandboxValidationError

Raised when the path is not absolute, file exceeds 4MB limit, or encoding is invalid.

SandboxPermissionDeniedError

Raised when the sandbox doesn't have permission to read the file.

SandboxNotFoundError

Raised when the sandbox no longer exists.

SandboxTimeoutError

Raised when the read operation times out (typically after 35 seconds).

SandboxFileError

Base exception for other file operation failures.