magicparse 🛸

Declarative parser

Usage

Parse content

import magicparse


schema = {
    "file_type": "csv",
    "has_header": False,
    "delimiter": ";",
    "fields": [
        {"key": "ean", "column-number": 2, "type": "str", "validators": [{"name": "regex-matches", "parameters": {"pattern": "^\\d{13}$"}}]},
        {"key": "label", "column-number": 3, "type": "str"},
        {"key": "family-code", "column-number": 8, "type": "str"},
        {"key": "vat", "column-number": 10, "type": "decimal"},
        {"key": "initial-price", "column-number": 11, "type": "decimal", "post-processors": {"name": "divide", "parameters": {"denominator": 100}}},
        {"key": "unit-of-measurement", "column-number": 12, "type": "int", "pre-processors": [{"name": "map", "parameters": {"values": {"K": 0, "A": 1, "L": 2}}}]},
        {"key": "volume", "column-number": 13, "type": "decimal"},
    ]
}


rows, errors= magicparse.parse(data="...", schema=schema)

Register a custom transform and parse content

from uuid import UUID
import magicparse

class GuidConverter(magicparse.Converter):
    @staticmethod
    def key() -> str:
        return "guid"

    def apply(self, value):
        return UUID(value)


magicparse.register(GuidConverter)

schema = {
    "file_type": "csv",
    "fields": [
        {"key": "shop-guid", "type": "guid", "column-number": 1}
    ],
}

rows, errors = magicparse.parse("13ec10cc-cc7e-4ee9-b091-9caa6d11aeb2", schema)
assert rows == [{"shop-guid": "13ec10cc-cc7e-4ee9-b091-9caa6d11aeb2"}]
assert not errors

Register a custom schema and parse content

import magicparse

class PipedSchema(magicparse.Schema):
    @staticmethod
    def key() -> str:
        return "piped"

    def get_reader(self, stream):
        for item in stream.read().split("|"):
            yield [item]

magicparse.register(PipedSchema)

schema = {
    "file_type": "piped",
    "fields": [
        {"key": "name", "type": "str", "column-number": 1}
    ]
}

rows, errors = magicparse.parse("Joe|William|Jack|Averell", schema)
assert not errors
assert rows == [{"name": "Joe"}, {"name": "William"}, {"name": "Jack"}, {"name": "Averell"}]

API

File types

• CSV (with or without header)
• Columnar

Fields

Types

• str
• int
• decimal
• datetime (timezone aware)
• time (timezone aware)

Pre-processors

• left-pad-zeroes
• map
• regex-extract
• replace
• strip-whitespaces
• left-strip

Validators

• regex-matches
• greater-than

Post-processors

• divide