Skip to main content

The robust validation library for flask

Project description

Flask Validity

The robust validation library for flask


pip3 install lablnet/validity


from flask import Flask
from validity.Validation import Validation 

app = Flask(__name__)
validation = Validation()

@validation .validate(
 "field": "title",
 "required": True,
 "type": "str",
 "min": 10,
 "max": 30,
 "regex": None
def index():
    return 'Web App with Python Flask!''', port=81)

This class used to validate any incoming json request to your flask route, it validate the request after validation passes then the request enters your route function.

It amins to allow you to write once and used a lot instead of validation request on every route it is better to do it once at top of your function.

It support number of parameter are as follow:

  1. field This is required parameter which indicate the field name you want to accpet.
  2. required This is not required parameter but if this not present any of below validation will not considered, its value either True or False
  3. type Which type of request value should be it support int, float, list, bool, dict and str
  4. min and max These are optional parameter but if one of them present other is required its used to indicate restriction to min and max length or value.
  5. regex It is optional parameter but It is used to validate request base on regex.
  6. email It is optional parameter it validate email.
  7. phone It is optional parameter it validate phone.
  8. file If validat file set this to true.
    1. size File size in bytes.
    2. ext File extension it accpet python list.
    3. mime File mime types, it accpet python list.

Returning Value

Validity support three method for returning the errors

  1. As json
    • Return as json array.
  2. As String
    • Return as string.
  3. As query string
    • Return redirect with query parameters.
  4. None
    • None mean it will do nothing but you can get the error with validator.Errors

You can pass these flags to validate as second argument.

@app.route('/process', methods=['POST', 'GET'])
"field": "name",
"required": True,
"type": "str",
def  process():
	 errors = validator.Errors
	 # rest of code..


Currently it support two languages out of the box that includes:

  1. English
  2. Urdu

You can set the language as below:

# ... 
validator  =  Validator("en")
# ...

You can add your langauge by sending PR and/or you can pass validator constructor language string as below, assume it will be your own language:

# ...
validator  =  Validator("en", {
"required": "The %s is required.",
"extension": "The %s extension is not allowed.",
"mime": "The %s mimetype is not allowed.",
"size": "The %s size is too large.",
"empty": "The %s must not be empty.",
"type": "The %s must be %s .",
"between": "The %s must be between %s and %s .",
"regx": "The %s must be in correct format.",
"phone": "The phone number should be valid.",
"email": "The email should be valid.",
"error": "Unable to decode the data."
# ...


Thank you for considering contributing to the validity! Feel free to create a pull request.

Contrubuting guide


  • GNU GPL3

Security Vulnerabilities

If you discover a security vulnerability within Validity, please send an e-mail to our team via All security vulnerabilities will be promptly addressed.

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distributions

No source distribution files available for this release. See tutorial on generating distribution archives.

Built Distribution

flask_validity-1.0.0-py2.py3-none-any.whl (19.2 kB view hashes)

Uploaded py2 py3

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page