python-mylib/mylib/mapping.py

"""
My hash mapping library
Mapping configuration
 {
    '[dst key 1]': {            # Key name in the result

     'order': [int],            # Processing order between destinations keys

     # Source values
     'other_key': [key],            # Other key of the destination to use as source of values
     'key' : '[src key]',            # Key of source hash to get source values
     'keys' : ['[sk1]', '[sk2]', ...],    # List of source hash's keys to get source values

     # Clean / convert values
     'cleanRegex': '[regex]', # Regex that be use to remove unwanted characters. Ex : [^0-9+]
     'convert': [function],   # Function to use to convert value : Original value will be passed
                              # as argument and the value retrieve will replace source value in
                              # the result
                              # Ex :
                              #  lambda x: x.strip()
                              #  lambda x: "myformat : %s" % x
     # Deduplicate / check values
     'deduplicate': [bool], # If True, sources values will be depluplicated
     'check': [function],   # Function to use to check source value : Source value will be passed
                            # as argument and if function return True, the value will be preserved
                            # Ex :
                            #  lambda x: x in my_global_hash
     # Join values
     'join': '[glue]',       # If present, sources values will be join using the "glue"

     # Alternative mapping
     'or': { [map configuration] }  # If this mapping case does not retreive any value, try to
                                    # get value(s) with this other mapping configuration
    },
    '[dst key 2]': {
     [...]
    }
}

Return format :
{
  '[dst key 1]': ['v1','v2', ...],
  '[dst key 2]': [ ... ],
  [...]
}
"""

import logging
import re

log = logging.getLogger(__name__)


def clean_value(value):
    """Clean value as encoded string"""
    if isinstance(value, int):
        value = str(value)
    return value


def get_values(dst, dst_key, src, m):
    """Extract sources values"""
    values = []
    if "other_key" in m:
        if m["other_key"] in dst:
            values = dst[m["other_key"]]
    if "key" in m:
        if m["key"] in src and src[m["key"]] != "":
            values.append(clean_value(src[m["key"]]))

    if "keys" in m:
        for key in m["keys"]:
            if key in src and src[key] != "":
                values.append(clean_value(src[key]))

    # Clean and convert values
    if "cleanRegex" in m and len(values) > 0:
        new_values = []
        for v in values:
            nv = re.sub(m["cleanRegex"], "", v)
            if nv != "":
                new_values.append(nv)
        values = new_values

    if "convert" in m and len(values) > 0:
        new_values = []
        for v in values:
            nv = m["convert"](v)
            if nv != "":
                new_values.append(nv)
        values = new_values

    # Deduplicate values
    if m.get("deduplicate") and len(values) > 1:
        new_values = []
        for v in values:
            if v not in new_values:
                new_values.append(v)
        values = new_values

    # Check values
    if "check" in m and len(values) > 0:
        new_values = []
        for v in values:
            if m["check"](v):
                new_values.append(v)
            else:
                log.debug("Invalid value %s for key %s", v, dst_key)
        values = new_values

    # Join values
    if "join" in m and len(values) > 1:
        values = [m["join"].join(values)]

    # Manage alternative mapping case
    if len(values) == 0 and "or" in m:
        values = get_values(dst, dst_key, src, m["or"])

    return values


def map_hash(mapping, src, dst=None):
    """Map hash"""
    dst = dst if dst else {}
    assert isinstance(dst, dict)
    for dst_key in sorted(mapping.keys(), key=lambda x: mapping[x]["order"]):
        values = get_values(dst, dst_key, src, mapping[dst_key])

        if len(values) == 0:
            if "required" in mapping[dst_key] and mapping[dst_key]["required"]:
                log.debug(
                    "Destination key %s could not be filled from source but is required", dst_key
                )
                return False
            continue

        dst[dst_key] = values
    return dst