Easy Validator

Validating user input is something you'll often need in Python projects. Checking emails, usernames, URLs, ZIP codes, and passwords can require repetitive regular expressions and validation logic.

The easy_validator module provides simple helpers for common validation tasks, allowing you to check whether values follow expected formats without writing the underlying validation logic yourself.

A small real-world example

Imagine you're creating a registration form where users need to provide an email address, username, and password.

```python id="h4x8sd" from py_simple import ( is_valid_email, is_valid_username, is_password_secure )

email = "hello@example.com" username = "user_name" password = "1andkrf!AG5"

print(is_valid_email(email)) print(is_valid_username(username)) print(is_password_secure(password))

Example output:

```text id="t2k6pf"
True
True
True

What happened?

is_valid_email() checks whether a string follows a valid email format.

is_valid_username() checks whether a username contains only letters, numbers, and underscores.

is_valid_zipcode() checks whether a value is a valid five-digit US ZIP code.

is_valid_url() checks whether a string follows a supported URL format.

is_password_secure() checks a password against several security requirements.

For example:

```python id="s7n3qm" from py_simple import is_valid_url, is_valid_zipcode

print(is_valid_url("https://example.com"))

True

print(is_valid_zipcode(12345))

True

## The Py_simple Way

```python id="j8v2nc"
from py_simple import (
    is_valid_email,
    is_valid_username,
    is_valid_zipcode,
    is_valid_url,
    is_password_secure
)

print(is_valid_email("hello@example.com"))
print(is_valid_username("user_name"))
print(is_valid_zipcode(12345))
print(is_valid_url("www.google.com"))
print(is_password_secure("1andkrf!AG5"))

The Traditional Way

Without py_simple, you would normally need to write the appropriate regular expressions and validation logic yourself:

```python id="r5k1zp" import re

email_pattern = r'[a-zA-Z_.%+-]+@[a-zA-Z0-9-]+.[a-zA-Z]+' username_pattern = r'^[a-zA-Z0-9_]+' zipcode_pattern = r'^[0-9]{5}$'

email_valid = bool( re.fullmatch(email_pattern, "hello@example.com") )

username_valid = bool( re.fullmatch(username_pattern, "user_name") )

zipcode_valid = bool( re.fullmatch(zipcode_pattern, str(12345)) )

For password validation, you would additionally need to manually count characters, check their types, and make sure characters aren't repeated.

The `easy_validator` helpers package these common validation patterns into simple, reusable functions.

## Validating emails and usernames

`is_valid_email()` checks whether an email follows the expected format:

```python id="c3n7vw"
from py_simple import is_valid_email

print(is_valid_email("hello@example.com"))
# True

print(is_valid_email("not-an-email"))
# False

is_valid_username() accepts usernames containing letters, numbers, and underscores:

```python id="x9q4mk" from py_simple import is_valid_username

print(is_valid_username("user_name"))

True

print(is_valid_username("user-name"))

False

## Validating URLs and ZIP codes

`is_valid_url()` checks common URLs:

```python id="p6d2fz"
from py_simple import is_valid_url

print(is_valid_url("www.google.com"))
# True

print(is_valid_url("https://example.com"))
# True

is_valid_zipcode() checks for a five-digit US ZIP code:

```python id="m8r5yx" from py_simple import is_valid_zipcode

print(is_valid_zipcode(12345))

True

print(is_valid_zipcode(1234))

False

## Checking password security

`is_password_secure()` checks that a password meets several requirements.

A password must have:

* At least 9 characters.
* At least 1 uppercase letter.
* At least 2 lowercase letters.
* At least 2 digits.
* At least 1 special character.
* No consecutive repeated characters.

For example:

```python id="f7c2ka"
from py_simple import is_password_secure

password = "1andkrf!AG5"

print(is_password_secure(password))

Output:

```text id="b9w4qt" True

A password that doesn't meet the requirements returns `False`:

```python id="v3m8sx"
print(is_password_secure("password"))
# False

Why use these helpers?

Instead of repeatedly writing regular expressions, character counters, and validation conditions, you can simply use:

python id="n2x6pk" is_valid_email(email) is_valid_username(username) is_valid_zipcode(zipcode) is_valid_url(url) is_password_secure(password)

These helpers keep common validation tasks simple, readable, and beginner-friendly while handling the underlying regular expressions and validation logic for you.