Wrapper libraries and idea of "built on top of"

• That said, why do we need to also import matplotlib if seaborn can do everything anyway? Is it simply because seaborn can only get so far and does not really access ALL the capabilities of the more sophisticated matplotlib? Matplotlib has a slightly harder syntax but we can tweak more with it. Is that correct?
• Importing seaborn does not automatically import matplotlib. However, in the case of the Python libraries Keras and Tensorflow, Keras is the API and wrapper library for TF and Keras does not work without the Tensorflow engine. TF is always imported implicitly or explicitly and needs to be there...That is not the case for the pair matplotlib and seaborn...Why?
• Do you have any other example of wrapper library in Python? Many libraries are built on top of other libraries. For example, pandas is built on top of numpy and matplotib. But "built on top" simply means that the these libraries started out from the skeleton of these other two libraries. It does not mean that pandas is a wrapper library for numpy or matplotlib...Correct?

fog37 said:

TL;DR Summary: Wrapper libraries and the backend software they support

Hello,
I understand that a software library is called "wrapper library" if it provides a level of abstraction to another library: we can use the wrapper library instead of using the backend library directly to have an easier and more convenient access to the backend library functionalities.
One example from the Python world is the pair of viz libraries Matplotlib and Seaborn. It is standard to always imported both two libraries together but we could import only one of them and use it alone.

fog37 said:

Seaborn is built on top of matplotlib and is said to be a wrapper library for matplotlib. That means that seaborn can do everything that matplotlib does.

fog37 said:

Seaborn is just an easier to use interface (API) to use all the functionalities of matplotlib under the hood.

fog37 said:

• That said, why do we need to also import matplotlib if seaborn can do everything anyway?

fog37 said:

• Is it simply because seaborn can only get so far and does not really access ALL the capabilities of the more sophisticated matplotlib? Matplotlib has a slightly harder syntax but we can tweak more with it. Is that correct?

fog37 said:

• Importing seaborn does not automatically import matplotlib. However, in the case of the Python libraries Keras and Tensorflow, Keras is the API and wrapper library for TF and Keras does not work without the Tensorflow engine. TF is always imported implicitly or explicitly and needs to be there...That is not the case for the pair matplotlib and seaborn...Why?

fog37 said:

• Do you have any other example of wrapper library in Python? Many libraries are built on top of other libraries. For example, pandas is built on top of numpy and matplotib. But "built on top" simply means that the these libraries started out from the skeleton of these other two libraries.

fog37 said:

• It does not mean that pandas is a wrapper library for numpy or matplotlib...Correct?

fog37 said:

It is standard to always imported both two libraries together but we could import only one of them and use it alone.

https://seaborn.pydata.org/installing.html said:

The basic invocation of pip will install seaborn and, if necessary, its mandatory dependencies.

[...]

Mandatory dependencies​

• numpy
• pandas
• matplotlib

jack action said:

According to the documentation, Seaborn cannot be used without numpy, pandas, and mathplotlib:

fog37 said:

I see. Thank you.

So numpy, pandas, matplotlib are required dependencies. Without them installed, seaborn does not work, i.e. it cannot be installed alone. However, it can be imported alone: in the code, I can simply type import seaborn as sns and everything works just fine. Under the hood, matplotlib and numpy do not get imported but do they still get "contacted" (bad term) by seaborn?

"""Utility functions, mostly for internal use."""
import os
import re
import inspect
import warnings
import colorsys
from contextlib import contextmanager
from urllib.request import urlopen, urlretrieve

import numpy as np
import pandas as pd
import matplotlib as mpl
from matplotlib.colors import to_rgb
import matplotlib.pyplot as plt
from matplotlib.cbook import normalize_kwargs

from .external.version import Version
from .external.appdirs import user_cache_dir

pasmith said:

Check the source code. seaborn.utils imports matplotlib, numpy and pandas:

Python:

"""Utility functions, mostly for internal use."""
import os
import re
import inspect
import warnings
import colorsys
from contextlib import contextmanager
from urllib.request import urlopen, urlretrieve

import numpy as np
import pandas as pd
import matplotlib as mpl
from matplotlib.colors import to_rgb
import matplotlib.pyplot as plt
from matplotlib.cbook import normalize_kwargs

from .external.version import Version
from .external.appdirs import user_cache_dir

fog37 said:

So the line import seaborn as sns does automatically import, under the cover, the libraries matplotlib, pandas, and numpy

fog37 said:

Thank you! Looking into.

So the line import seaborn as sns does automatically import, under the cover, the libraries matplotlib, pandas, and numpy... but that does not mean we can use those other libraries and their methods without explicitly importing them as well...