safeshield 1.6.1

Library for Help Validation Control

Safe Shield

Safe Shield is a robust Python library designed to validating HTTP requests and input data.

This project is licensed under the AGPLv3 License - see the LICENSE file for details

Table of Contents

• Installation
• Overview
  • Usage
  • Validation Data
  • Error Messages
  • Attributes Custom
  • Rules
  • Custom Rule
• Example
• LICENSE

Installation

Use the package manager pip to isntall Safe Shield.

pip install safeshield

Usage

User should pass request dictionary and rules dictionary for validation data in the request.

Please see examples below:

from validator import Validator

request = {
  "name": "Wunsun",
  "email": "[e-mail]",
  "age": 20,
}

rules = {
  "name": "required",
  "email": "required|email",
  "age": "required|integer|min:18",
}

validated_data = Validator(request, rules).validate() # Validated data returned

Validator().validate() returns either validated data or False

Validation Data

Rule Format

You can define multiple rules for each field as a string, tuple, or list.

• String Format

rules = {
  "name": "required",
  "email": "required|email",
  "age": "required|integer|min:18",
}

• List Format

rules = {
  "name": ["required"],
  "email": ["required"， "email"],
  "age": ["required"，"integer", "min:18"],
}

• Tuple Format

rules = {
  "name": ("required"),
  "email": ("required"， "email"),
  "age": ("required"，"integer", "min:18"),
}

All rules can be invoked either as a class instantiation or via method calls from the Rule class (e.g., Required()) or methods (e.g., Rule.required()).

from validator.rules import Rule, Required, Email

rules = {
  "name": Required(),  # Single rule (no brackets needed)
  "email": [Required(), Email()],  # Initialization Rule Class
  "age": [Rule.required()，Rule.integer(), Rule.min(18)],  # Call rule from Rule Class
}

Nested Rules:

Nested data validation, use dot notation like 'user.name' to access deep fields or wildcards like 'orders.*.id' to validate all array items. The system automatically checks all nested levels and returns clear error messages pointing to exact validation failures."

rules = {
    "user.name": Required(),  # Top-level field
    "user.contact.email": [Required(), Email()],  # Nested field
    "orders.*.id": Required(),  # Wildcard for list items
}

Error Messages

This validator enables users to track validation failures and receive corresponding error messages.

Basic Error Validation

This demonstrates fundamental validation failures for required fields and data types:

from validator import Validator

request = {
  "name": "",  # Empty value
  "email": "[e-mail]",
]

rules = {
  "name": "required|string"
}

validator = Validator(request, rules)
validator.validate()

"""
validator.has_errors -> True
validator.errors     -> {"name": ["The name field is required.", "The name must be a string"]}
"""

• Output Explanation:
  • validator.has_errors → True (Indicates validation failed)
  • validator.errors → Returns detailed error messages:
    • For the name field:
      • "The name field is required." - Because the value is empty
      • "The name must be a string." - Empty string fails type validation

Nested Error Validation

Validates complex nested structures (objects/arrays) with precise error location:

from validator import Validator

data = {
    "user": {
        "name": "Alice",
        "contact": {"email": "[e-mail]"} # Invalid dns email format
    },
    "orders": [
        {"id": 1, "price": "One hundred"}, # Invalid price type
        {"id": 2, "price": 200}  # Valid entry
    ]
}

rules = {
  "user.name": "required",
  "user.contact.email": "email:dns",  # Requires valid DNS email records
  "orders.*.price": "required|integer", # Wildcard validates all array item
}

validator = Validator(request, rules)
validator.validate()

"""
validator.has_errors -> True
validator.errors     -> {
                          "user.contact.email": ["The email must be a valid email with valid DNS records."],
                          "orders.0.price": ["The price must be a number"]
                        }
"""

• Output Explanation:
  • validator.has_errors → True
  • validator.errors → Pinpoints exact failures:
    • user.contact.email: Fails DNS validation
    • orders.0.price: First array item fails integer validation
    • Note how array indices (0, 1, etc.) are automatically identified

Custom Error Message

Override default messages with user-friendly alternatives:

messages = {
  "user.contact.email": "This email is invalid"
}

validator = Validator(request, rules, messages)
validator.validate()

"""
validator.has_errors -> True
validator.errors     -> {
                          "user.contact.email": ["This email is invalid"],
                          "orders.0.price": ["The price must be a number"]
                        }
"""