arrayfile 0.0.1

Arrays backed by disk

arrayfile

A file-backed numeric array using struct.pack. Does not support inserts or slicing.

Smaller than relying on numpy though.

Installation

pip install arrayfile

Usage

Temporary Array

This creates an array in your temp dir:

from arrayfile import Array

# Create a temporary array with float data
arr = Array('f')
arr.append(3.14)
arr.append(2.71)
arr.extend([1.41, 1.73])

print(f"Length: {len(arr)}")
print(f"Values: {[arr[i] for i in range(len(arr))]}")
arr.close()  # Clean up resources

Persistent Array

You can use the same file, if you want to persist your data across sessions:

from arrayfile import Array

# Create and populate an array file
arr = Array('i', 'numbers.array', 'w+b')
for i in range(1000):
    arr.append(i * 2)
arr.close()

# Reopen the same file later
arr = Array('i', 'numbers.array', 'r+b')
print(f"Array has {len(arr)} elements")
print(f"First element: {arr[0]}")
print(f"Last element: {arr[-1]}")

# Add more data
arr.append(2000)
arr.close()

Context manager

It has a finalizer in case you forget to call close(), but if you like to keep your code tidy, you can use a context manager, like so:

from arrayfile import Array

# Using double precision floats with context manager
with Array('d', 'measurements.array', 'w+b') as arr:
    arr.extend([3.141592653589793, 2.718281828459045, 1.4142135623730951])

    print(f"Stored {len(arr)} precise measurements")
    for i, value in enumerate(arr):
        print(f"  {i}: {value:.15f}")