cite_exchange

A Python library for parsing and working with CITE EXchange (CEX) format data.

Overview

cite_exchange provides tools for reading and processing data in CITE EXchange format, a line-oriented text format for managing structured data about scholarly resources. CEX files are organized into labeled blocks, where each block contains tabular data relevant to a specific resource type.

Installation

pip install cite_exchange

Requirements

• Python 3.13.7+

Quick Start

from cite_exchange.blocks import CexBlock

# Parse from a string
with open('data.cex', 'r') as f:
    content = f.read()
all_blocks = CexBlock.from_text(content)

# Parse directly from a file
all_blocks = CexBlock.from_file('data.cex')

# Parse directly from a URL
all_blocks = CexBlock.from_url('https://example.com/data.cex')

# Filter by label
ctsdata_blocks = CexBlock.from_file('data.cex', label='ctsdata')

# Access block data
for block in ctsdata_blocks:
    print(f"Label: {block.label}")
    print(f"Data lines: {len(block.data)}")
    for line in block.data:
        print(f"  {line}")

API Reference

CexBlock

A dataclass representing a labeled block of text data from a CEX source.

marimo + WASM

The package is pure Python and can be used in marimo notebooks compiled to HTML/WASM.

In a marimo notebook, install from a wheel URL (or local wheel served over HTTP):

import micropip
await micropip.install("https://<your-host>/cite_exchange-0.2.0-py3-none-any.whl")

from cite_exchange import CexBlock

For browser environments, prefer CexBlock.from_text(...) with already-loaded content.

An example marimo notebook script is included at examples/marimo_wasm_notebook.py.

Run locally:

marimo edit examples/marimo_wasm_notebook.py

Then export with your installed marimo HTML/WASM export command (this can vary by version).

Attributes

• label (str): The label identifier for this block (without the #! prefix)
• data (list[str]): List of data lines in this block, excluding empty lines and comments

Methods

CexBlock.from_text(src: str, label: str = None) -> list[CexBlock]

Parse CEX-formatted text and create CexBlock instances.

Parameters:

• src (str): The CEX-formatted text to parse
• label (str, optional): If specified, only return blocks matching this label

Returns: A list of CexBlock instances

Parsing Rules:

• Label lines begin with #! and define the start of a new block
• Data lines are non-empty and don't start with // (comments are ignored)
• Multiple blocks can have the same label type
• Empty lines and comment lines are excluded from block data

Example:

# Parse all blocks
blocks = CexBlock.from_text(cex_content)

# Parse only specific label type
catalog_blocks = CexBlock.from_text(cex_content, label='ctscatalog')

Utility Functions

labels(s: str) -> list[str]

Extract all unique labels from a CEX-formatted string.

Returns: Sorted list of unique label names

from cite_exchange.blocks import labels

with open('data.cex', 'r') as f:
    content = f.read()

label_list = labels(content)
print(label_list)  # ['citecollections', 'citedata', 'citeproperties', ...]

valid_label(label: str) -> bool

Check if a label is valid according to CEX format specification.

Valid labels:

• cexversion
• citelibrary
• ctsdata
• ctscatalog
• citecollections
• citeproperties
• citedata
• imagedata
• datamodels
• citerelationset
• relationsetcatalog

from cite_exchange.blocks import valid_label

print(valid_label('ctsdata'))    # True
print(valid_label('invalid'))    # False

CEX Format Overview

CEX (CITE EXchange) is a line-oriented format for exchanging data about scholarly resources. Key features:

• Line-oriented structure: Data organized into lines and blocks
• Labeled blocks: Each block starts with a #!label line
• Tabular data: Blocks contain pipe-delimited (|) or other delimited data
• Comments: Lines starting with // are comments and ignored
• Empty lines: Empty lines are ignored

Example CEX Content

#!ctscatalog
urn|citationScheme|groupName|workTitle
urn:cts:greekLit:tlg0012.tlg001:|book|Homer|Iliad

#!ctsdata
urn:cts:greekLit:tlg0012.tlg001:1.1|Μῆνις ἀ εἴδε θεά
urn:cts:greekLit:tlg0012.tlg001:1.2|Πηληϊάδεω Ἀχιλῆος

Testing

The package includes comprehensive unit tests covering all functionality:

python -m pytest test/test_blocks.py

Test data files are included in test/data/:

• burneysample.cex: Sample CEX data from the Homer Multitext project
• laxlibrary1.cex: Sample CITE collection data

License

See LICENSE file for details.

References

• CITE Architecture
• Homer Multitext Project