Function and classes in python

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I have surfed online but still not sure when we do

import matplotlib.pyplot

matplotlib is a file ? and pyplot is a class ? Could some one explain how they are structured.

Also all libraries that we get, can we see code for them .In Pycharm I just need to press ctrl+left click. But will it work for lets say a base function like casting operator - int().

Also for above example for file matplotlib how can I see all the possible functions and classes in them , is there any such function ?


import matplotlib

means that matplotlib is a "module", which is a namespace. it also means that matplotlib.pyplot is a module, because that's what the import statement does. It loads modules.

So pyplot is not a class. And Python classes should start with capital letters, too.

If this import succeeds, it means that "magically", python at runtime knows what matplotlib is, because python has a path of places in your filesystem to look. The list of places is determined when Python is installed.

If you think of it as matplotlib.py, you'll conceptually be correct. When you import a module, python will look for a file with that name in its path. As with most library packaging systems, the import statement could be abstracting some actual complexity. Big libraries can be split over multiple files and so on.

The module pyplot can only be found by first accessing matplotlib. This could be mapped to a subdirectory in the file system. Directories which contain sub-modules are marked via an __init__.py file and if you search to learn more about __init__.py files, you will learn about the topic of python modules.

The import statement you gave as an example lets you refer to matplotlib.pyplot to access actually useful things, such as functions and classes.

So if there was a function "show()" you could refer to

matplotlib.pyplot.show() 

in your code

def show_chart():
    matplotlib.pyplot.show() #made-up example

if you had instead done

from matplotlib import pyplot

you would refer to

pyplot.show()

which saves some typing.

if pyplot has a class "Chart", you could do

my_chart = pyplot.Chart()

PS there is a version of the python console called ipython If it is installed on your system, Pycharm will use it when you do Tools -> Python Console.

Try

>>> import datetime
>>> ??datetime

the ?? query tells you a lot about the module, although it actually just accesses documentation that you can also access in other ways, as you have discovered If that example doesn't work, ipython is not installed, so google for that. It has some very nice shortcuts.

9. Classes — Python 3.8.5 documentation, Methods in objects are functions that belong to the object. Let us create a method in the Person class: Example. Insert a function that prints a greeting, and execute � A class is a user-defined blueprint or prototype from which objects are created. Classes provide a means of bundling data and functionality together. Creating a new class creates a new type of object, allowing new instances of that type to be made. Each class instance can have attributes attached to it for maintaining its state.


matplotlib is a package, when you you import it, to Python it looks like any module.

pyplot is a module as well, but it's a module inside the matplotlib package.

You can ask Python itself:

>>> from matplotlib import pyplot
>>> type(pyplot)
<class 'module'>
>>> import matplotlib
>>> type(matplotlib)
<class 'module'>

A class would just be a type:

>>> from matplotlib import Parameter
>>> type(Parameter)
<class 'type'>

And to see what a module (or a class) has to offer, use dir():

>>> dir(matplotlib)
['LooseVersion', 'MatplotlibDeprecationWarning', 'MutableMapping', 'Parameter', 'Path', 'RcParams', 'URL_REGEX', '_DATA_DOC_APPENDIX', '_DATA_DOC_TITLE', '_ExecInfo', '__bibtex__', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__path__', '__spec__', '__version__', '_add_data_doc', '_all_deprecated', '_check_versions', '_cm', '_cm_listed', '_color_data', '_constrained_layout', '_create_tmp_config_or_cache_dir', '_deprecated_ignore_map', '_deprecated_map', '_deprecated_remain_as_none', '_ensure_handler', '_error_details_fmt', '_get_config_or_cache_dir', '_get_data_path', '_get_executable_info', '_get_xdg_cache_dir', '_get_xdg_config_dir', '_image', '_init_tests', '_label_from_arg', '_layoutbox', '_log', '_logged_cached', '_mathtext_data', '_open_file_or_url', '_path', '_preprocess_data', '_pylab_helpers', '_rc_params_in_file', '_replacer', '_version', 'afm', 'artist', 'atexit', 'axes', 'axis', 'backend_bases', 'backend_tools', 'backends', 'bezier', 'blocking_input', 'category', 'cbook', 'checkdep_dvipng', 'checkdep_ghostscript', 'checkdep_inkscape', 'checkdep_pdftops', 'checkdep_ps_distiller', 'checkdep_usetex', 'cm', 'collections', 'colorbar', 'colors', 'compare_versions', 'container', 'contextlib', 'contour', 'cycler', 'dates', 'dedent', 'defaultParams', 'default_test_modules', 'docstring', 'dviread', 'figure', 'font_manager', 'fontconfig_pattern', 'ft2font', 'functools', 'get_backend', 'get_cachedir', 'get_configdir', 'get_data_path', 'get_home', 'get_label', 'get_py2exe_datafiles', 'gridspec', 'image', 'importlib', 'inspect', 'interactive', 'is_interactive', 'is_url', 'legend', 'legend_handler', 'lines', 'locale', 'logging', 'markers', 'mathtext', 'matplotlib_fname', 'mlab', 'mplDeprecation', 'namedtuple', 'numpy', 'offsetbox', 'os', 'patches', 'path', 'pprint', 'projections', 'pyplot', 'quiver', 'rc', 'rcParams', 'rcParamsDefault', 'rcParamsOrig', 'rc_context', 'rc_file', 'rc_file_defaults', 'rc_params', 'rc_params_from_file', 'rcdefaults', 'rcsetup', 're', 'sanitize_sequence', 'scale', 'set_loglevel', 'shutil', 'spines', 'stackplot', 'streamplot', 'style', 'subprocess', 'sys', 'table', 'tempfile', 'test', 'texmanager', 'text', 'textpath', 'ticker', 'tight_bbox', 'tight_layout', 'tk_window_focus', 'transforms', 'tri', 'units', 'use', 'validate_backend', 'widgets']

Python Classes, Objects get their variables and functions from classes. Classes are essentially a template to create your objects. A very basic class would look something like this: class MyClass: variable = "blah" def function(self): print("This is a message inside the class.") Classes and Objects Objects are an encapsulation of variables and functions into a single entity. Objects get their variables and functions from classes. Classes are essentially a template to create your objects.


You can get the detailed structure of the matplotlib project at https://github.com/matplotlib/matplotlib/tree/master/lib/matplotlib

Make sure that your IDE has path set to where you have installed the libraries.

Classes and Objects - Learn Python, Those functions are called methods. Attributes: You can define the following class with the name Snake. This class will have an attribute name . >� The function allows us to implement code reusability. There are three kinds of functions − Built-in functions ( As the name suggests, these functions come with the Python language, for example, help() to ask for any help, max()- to get maximum value, type()- to return the type of an object and many more.)


Python Classes and Objects [With Examples], Class creates a user-defined data structure, which holds its own data members and member functions, which can be accessed and used by� IMHO: object oriented programming in Python sucks quite a lot. The method dispatching is not very straightforward, you need to know about bound/unbound instance/class (and static!) methods; you can have multiple inheritance and need to deal with legacy and new style classes (yours was old style) and know how the MRO works, properties


Classes and Objects I Tutorials & Notes | Python, Notice how Python automatically passes the class as the first argument to the function when we call MyClass.classmethod() . Calling a method in Python through� The __init__ function is a reserved function in classes in Python which is automatically called whenever a new object of the class is instantiated. As a regular function, the init function is also defined using the def keyword.


Python Classes and Objects, However, in Python, they consist of functions as well as information. In short, a Python class is for defining a particular type of object. Because�