marcgrep 1.2.0

search MARC files for regex matches

marcgrep

A CLI for searching MARC files like MARCgrep.pl but in Python and a bit different syntax.

marcli is also a similar project that's faster but a little less flexible.

Installation

Python 3.9 or later.

pipx install marcgrep # install globally with pipx
pip install marcgrep # or use pip/pip3

Usage

# general command format - pass one or more files or pipe stdin
marcgrep OPTIONS FILE1.mrc FILE2.mrc
cat FILE.mrc | marcgrep OPTIONS
# full usage information
Usage: marcgrep [OPTIONS] [FILES]...

  Find MARC records matching patterns in a file.

Options:
  -h, --help           Show this message and exit.
  -c, --count          Count matching records
  -i, --include TEXT   Include matching records (repeatable)
  -e, --exclude TEXT   Exclude matching records (repeatable)
  -f, --fields TEXT    Comma-separated list of fields to print
  -l, --limit INTEGER  Limit number of records to process
  --color              Colorize mnemonic MARC output
  --invert             Invert color scheme (for light terminal backgrounds)
  --version            Show the version and exit.

The --include and --exclude flags can be used multiple times to specify multiple criteria. They accept a pattern which is a sort of comma-separated filter expression for matching MARC fields. Examples:

# records with a 780 field
marcgrep -i 780 FILE.mrc
# records with Ulysses in the 245 field
marcgrep -i '245,Ulysses' FILE.mrc
# titles _without_ "Collected Poems" in the 245 ‡a subfield
marcgrep -e '245,a,Collected Poems' FILE.mrc
# titles with second indicator = 4 that do not start with "The "
marcgrep -i '245,,4,,^(?!The )' FILE.mrc

The meaning of the filter expression's components depends upon their number:

• 1: field, 910 -> 910 is in record
• 2: field and value (regular expression), 100,Lorde -> 100 contains string "Lorde"
• 3: field, subfield, and value, 506,a,Open Access -> 506‡a contains string "Open Access"
• 4: field, subfield, first indicator, and value, 856,0,u,@lcsh\.gov -> 856‡u with 1st indicator 0 contains string "@lcsh.gov"
• 5: field, subfield, first & second indicators, and value, 245,0,4,a,The Communist Manifesto

The intention of this syntax is to facilitate searching subfields and field values more easily than MARCgrep.pl since we care about them more often than indicators. To ignore a component but use one of lesser priority, leave the component empty. For instance, 856,s, refers to records with an 856 field with an s subfield but the trailing comma means we don't care about the subfield's value. The pattern 245,,4,, refers to records with a 245 field with a second indicator of 4 regardless its subfields or value.

To use a literal comma in a value pattern, include all the other components. For instance, to search for "Morrison, Toni" anywhere in a 100 field, use 100,,,,Morrison, Toni.

Multiple criteria are combined with logical AND. Multiple --include flags is narrower than one, as is an --include and an --exclude.

Color & Formatting

The --color flag lets you pick colors for various parts of a MARC record using environment variables. You can pick from the available termcolor colors. The defaults are:

Component	Color	Var
Tag	cyan	MARC_TAG_COLOR
Indicator	light_yellow	MARC_INDICATOR_COLOR
Subfield code	green	MARC_SUBFIELD_COLOR
Data	white	MARC_DATA_COLOR

There is an inverted color scheme available with the --invert flag for use with light (e.g. white) terminal backgrounds.

You can also configure the subfield delimiter character and the symbol for an empty indicator. Those defaults are:

Symbol	Var
‡	MARC_SUBFIELD_DELIMITER
_	MARC_EMPTY_INDICATOR

Development

Poetry is used for development.

poetry install # install dependencies
poetry run pytest # run tests
poetry build # build package, used in CI

Any tag triggers a release to Test PyPI. Any tag beginning with the letter v requires manual approval to be released to PyPI and GitHub. There are protection rules on the pypi and testpypi environments to this effect, too.

License

MIT © Eric Phetteplace 2024.