userprovided 0.8.1

A library to check user input for validity and / or plausibility

userprovided

The Python package userprovided checks input for validity and / or plausibility. For example it can check whether a string is a valid email address or an URL. It can do more complicated tasks like checking a dictionary for valid and needed keys. It also contains some functionalities to convert input into a more rigid format (like the string 'October 3, 1990' into '1990-10-03').

There are similar projects out there. The reasons to write another library:

• Extensive testing.
• The code has type hints (PEP 484).
• Its sister-projects like exoskeleton and salted need some special features. This reduces the dependency on a third party to apply patches or to keep up with development.
• Modularity

Update and Deprecation Policy

• No breaking changes in micro-versions.
• It makes no sense to duplicate functionality already available in the Python Standard Library. Therefore, if this package contains functionality that becomes superseded by the Standard Library, it will start to log a depreciation warning. The functionality itself is planned to stay available for at least a major version of userprovided and as long as Python versions not containing this functionality are supported.

Documentation

Installation

Install exoskeleton using pip or pip3. For example:

sudo pip3 install userprovided

You may consider using a virtualenv.

To upgrade to the latest version accordingly:

sudo pip install userprovided --upgrade

Check a Parameter Dictionary

If your application accepts parameters in the form of a dictionary, you have to test if all needed parameters are provided and if there are any unknown keys (maybe due to typos). There is a method for that:

userprovided.parameters.validate_dict_keys(
    dict_to_check = {'a': 1, 'b': 2, 'c': 3},
    allowed_keys = {'a', 'b', 'c', 'd'},
    necessary_keys = {'b', 'c'})

Returns True if the dictionary dict_to_check contains only allowed keys and all necessary keys are present.

Normalize URLs

Normalize an URL means:

• remove whitespace around it,
• convert scheme and hostname to lowercase,
• remove ports if they are the standard port for the scheme,
• remove duplicate slashes from the path,
• remove fragments (like #foo),
• remove empty elements of the query part,
• order the elements in the query part by alphabet

url = ' https://www.Example.com:443//index.py?c=3&a=1&b=2&d='
userprovided.url.normalize_url(url)
# returns: https://www.example.com/index.py?a=1&b=2&c=3

Check Email-Addresses

userprovided.mail.is_email(None)
# => False

userprovided.mail.is_email('[e-mail]')
# => True

Check URLs

To check whether a string is a valid URL - including a scheme (like https) - use userprovided.url.is_url.

userprovided.url.is_url('https://www.example.com')
# => True
userprovided.url.is_url('www.example.com')
# => False

You can insist on a specific scheme:

userprovided.url.is_url('https://www.example.com', ('ftp'))
# => False (Schema does not match permitted)

userprovided.url.is_url('ftp://www.example.com', ('ftp'))
# => True

File Hashes

You can check whether a specific hash method is available. This will raise a ValueError for MD5 and SHA1 even if they are available, because they are deprecated.

print(userprovided.hash.hash_available('md5'))
# => ValueError because md5 is deprecated

print(userprovided.hash.hash_available('sha256'))
# => True on almost any system

You can calculate hash sums for files. If you do not provide the method, this defaults to SHA256. Other supported methods are SHA224 and SHA512.

# returns the hash of the file as a string:
userprovided.hash.calculate_file_hash(pathlib.Path('./foo.txt'))

Check and Normalize Dates

userprovided.date.date_exists(2020, 2, 31)
# => False

userprovided.date.date_en_long_to_iso('October 3, 1990')
# => '1990-10-03'

Other Functionality

### Cloud ###

userprovided.cloud.is_aws_s3_bucket_name('foobar')
# => True

### Parameters ###

userprovided.parameters.convert_to_set(list)
# => Convert a string, a tuple, or a list into a set
# (i.e. no duplicates, unordered)

### Ports ###

userprovided.port.port_in_range(int)
# Checks if the port is integer and within the
# valid range from 0 to 65536.