field-mapper 0.2.2

Field Mapper a Python library for seamless data field validation, transformation, and mapping with support for types, lengths, and custom rules.

Field Mapper: Documentation

Field Mapper is a Python library designed for validating, mapping, and transforming data fields. It is particularly useful for integrating third-party systems, ensuring compatibility when third-party fields and internal system fields differ. The library supports type checking, length constraints, optional fields, custom validation rules, and seamless data transformation for structured data validation.

Installation

Install the library using pip

pip install field-mapper

Quick Start

1. Define Fields Create a field map dictionary. Also, Create a fields dictionary to define the rules for your data fields.

field_map = {
    "name": "full_name",
    "email": "contact_email",
    "phone": "mobile_number",
    "income": "monthly_income"
}
fields = {
    "name": {"type": str, "max_length": 50, "required_field": True, "required_value":True},
    "email": {"type": str, "max_length": 100, "required_field": True, "required_value":True},
    "phone": {"type": str, "max_length": 15, "required_field": False, "required_value":False},
    "income": {"type": int, "max_length": 15, "required_field": True, "required_value":False}
}

2. Prepare Data The input should be a list of dictionaries.

data = [
    {"name": "Alice", "email": "[e-mail]", "phone": "1234567890"},
    {"name": "Bob", "email": "charlieexample.com", "phone": "453543535", "income":0},
    {"name": "Charlie", "email": "[e-mail]", "phone": "34534523", "income":0}
]

3. Data Process Use the process method to check and transform the data.

from field_mapper import FieldMapper

field_map = {
    "name": "full_name",
    "email": "contact_email",
    "phone": "mobile_number",
    "income": "monthly_income"
}

fields = {
    "name": {"type": str, "max_length": 50, "required_field": True, "required_value":True},
    "email": {"type": str, "max_length": 100, "required_field": True, "required_value":True},
    "phone": {"type": str, "max_length": 15, "required_field": False, "required_value":False},
    "income": {"type": int, "max_length": 15, "required_field": True, "required_value":False}
}

data = [
    {"name": "Alice", "email": "[e-mail]", "phone": "1234567890"},
    {"name": "Bob", "email": "charlieexample.com", "phone": "453543535", "income":0},
    {"name": "Charlie", "email": "[e-mail]", "phone": "34534523", "income":0}
]

mapper = FieldMapper(fields, field_map)
processed_data = mapper.process(data)
print(processed_data)
print(mapper.error)

4. Custom Validation Define custom validation logic for specific fields.

def validate_email(value):  
    import re  
    if not re.match(r"[^@]+@[^@]+\.[^@]+", value):  
        raise ValueError(f"Invalid email address: {value}")  

#Add the custom validator in the field definition:
field_map = {
    "name": "full_name",
    "email": "contact_email",
    "phone": "mobile_number",
    "income": "monthly_income"
}
fields = {
    "name": {"type": str, "max_length": 50, "required_field": True, "required_value":True},
    "email": {"type": str, "max_length": 100, "required_field": True, "required_value":True, "custom": validate_email},
    "phone": {"type": str, "max_length": 15, "required_field": False, "required_value":False},
    "income": {"type": int, "max_length": 15, "required_field": True, "required_value":False}
}

data = [
    {"name": "Alice", "email": "[e-mail]", "phone": "1234567890"},
    {"name": "Bob", "email": "charlieexample.com", "phone": "453543535", "income":0},
    {"name": "Charlie", "email": "[e-mail]", "phone": "34534523", "income":0}
]
mapper = FieldMapper(fields, field_map)
processed_data = mapper.process(data)
print(processed_data)
print(mapper.error)

5. Optional Fields Mark fields as optional with required_field: False.

fields = {
    "phone": {"type": str, "max_length": 15, "required_field": False},
}

6. Required Value If required_value=True is set, their presence is mandatory and values can't be empty.

fields = {"email": {"type": str, "max_length": 100, "required_field": True, "required_value":True}

7. Skip Duplicates Data If skip_duplicate=True is set, Skip duplicate data. Raises:DuplicatesDataError: If duplicate entries are found.

from field_mapper.mapper import FieldMapper

field_map = {
    "name": "full_name",
    "email": "contact_email",
    "phone": "mobile_number",
    "income": "monthly_income"
}
fields = {
    "name": {"type": str, "max_length": 50, "required_field": True, "required_value":True},
    "email": {"type": str, "max_length": 100, "required_field": True, "required_value":True},
    "phone": {"type": str, "max_length": 15, "required_field": False, "required_value":False},
    "income": {"type": int, "max_length": 15, "required_field": True, "required_value":False}
}
data = [
    {"name": "Charlie", "email": "[e-mail]", "phone": "888888", "income":0},
    {"name": "Charlie", "email": "[e-mail]", "phone": "444444", "income":0},
    {"name": "Charlie", "email": "[e-mail]", "phone": "444444", "income":0}
]
mapper = FieldMapper(fields, field_map)
processed_data = mapper.process(data, skip_duplicate=True)
print("Output:", processed_data)
print("Error:",mapper.error)

8. Get Nested Data

from field_mapper.mapper import FieldMapper

field_map = {
    "name": "full_name",
    "email[0]": "contact_email",
    "phone.phone_two": "mobile_number",
    "income[0].Jan": "monthly_income",
    "year_salary[].year": "salary"
}
data = [
    {
        "name": "Alice",
        "email": ["[e-mail]", "[e-mail]"],
        "phone": {"phone_one": '22222', "phone_two": "2332432"},
        "income": [{"Jan": 2000, "Feb": 3000}],
        "year_salary": [
            {"year": "2020", "Jan": 2000, "Feb": 3000},
            {"year": "2021", "Jan": 2000, "Feb": 3000}
        ]
    }
]
fields = {
    "name": {"type": str, "position": "name", "max_length": 50, "required_field": True, "required_value": True},
    "email": {"type": list, "position": "email[0]", "max_length": 100, "required_field": True, "required_value": True},
    "phone": {"type": dict, "position": "phone.phone_two", "required_field": True, "required_value": True},
    "income": {"type": list, "position": "income[0].Jan", "required_field": True, "required_value": True},
    "year_salary": {"type": list, "position": "year_salary[].year", "required_field": True, "required_value": True}
}
mapper = FieldMapper(fields=fields, field_map=field_map)
processed_data = mapper.process(data, skip_duplicate=True)
print("Output:", processed_data)
print("Error:",mapper.error)

#Output: [{'full_name': 'Alice', 'contact_email': '[e-mail]', 'mobile_number': '2332432', 'monthly_income': 2000, 'salary': ['2020', '2021']}]
#Error: []

Example usage

from field_mapper import FieldMapper


def validate_email(value: str) -> bool:
    return "@" in value and "." in value

field_map = {
    "name": "full_name",
    "email": "contact_email",
    "phone": "mobile_number",
    "income": "monthly_income"
}

fields = {
    "name": {"type": str, "max_length": 50, "required_field": True, "required_value":True},
    "email": {"type": str, "max_length": 100, "required_field": True, "required_value":True, "custom": validate_email},
    "phone": {"type": str, "max_length": 15, "required_field": False, "required_value":False},
    "income": {"type": int, "max_length": 15, "required_field": True, "required_value":False}
}

data = [
    {"name": "Alice", "email": "[e-mail]", "phone": "1234567890"},
    {"name": "Bob", "email": "charlieexample.com", "phone": "453543535", "income":0},
    {"name": "Charlie", "email": "[e-mail]", "phone": "34534523", "income":0}
]
mapper = FieldMapper(fields, field_map)
processed_data = mapper.process(data)
print(processed_data)
print(mapper.error)

Contributors

• Md Lutfor Rahman