Import Markdown Python



  1. Import Markdown Python Code
  2. Import Markdown Python Tutorial
  3. Import Markdown Python Example
  4. Python Markdown Tutorial

Import markdown content = markdown.markdown(md) print(content) We are using the markdown library to do the conversion. This takes a markdown format string and returns an html string. Based on the markdown code above, the html content string will be.

mistletoe is a Markdown parser in pure Python, designed to be fast, modular and fully customizable.

  • Convert Markdown to HTML in Python The easiest way to convert is just use a string for input and a string for output. Import markdown # Simple conversion in memory mdtext = '# Hellonn.Text.' html = markdown.markdown(mdtext) print(html) To use files for input and output instead.
  • Official examples and reference documentation for dcc.Markdown. Dcc.Markdown is a dashcorecomponents component.
  • Def help(self): ' Prints general help information, or specific usage information of a function if provided:param function: an optional function ' from IPython.display import Markdown, display def printmd(string): display(Markdown(string)) # Check whether the request is for some specific function #if function is not None: # printmd(self.function.doc) # If not then offer the general help menu #else.

mistletoe is not simply a Markdown-to-HTML transpiler. It is designed, from the start, to parse Markdown into an abstract syntax tree. You can swap out renderers for different output formats, without touching any of the core components.

Remember to spell mistletoe in lowercase!

Features

  • Fast: mistletoe is as fast as the fastest implementation currently available: that is, over 4 times faster than Python-Markdown, and much faster than Python-Markdown2. Try the benchmarks yourself by running:

  • Modular: mistletoe is designed with modularity in mind. Its initial goal is to provide a clear and easy API to extend upon.

  • Customizable: as of now, mistletoe can render Markdown documents to LaTeX, HTML and an abstract syntax tree out of the box. Writing a new renderer for mistletoe is a relatively trivial task.

Installation

mistletoe requires Python 3.3 and above, including Python 3.7, the current development branch. It is also tested on PyPy 5.8.0. Install mistletoe with pip:

Alternatively, clone the repo:

See the contributing doc for how to contribute to mistletoe.

Usage

From the command-line

pip installation enables mistletoe's commandline utility. Type the following directly into your shell:

This will transpile foo.md into HTML, and dump the output to stdout. To save the HTML, direct the output into a file:

Running mistletoe without specifying a file will land you in interactive mode. Like Python's REPL, interactive mode allows you to test how your Markdown will be interpreted by mistletoe:

Typing Ctrl-D tells mistletoe to interpret your input. Ctrl-C exits the program.

Basic usage

Here's how you can use mistletoe in a Python script:

mistletoe.markdown() uses mistletoe's default settings: allowing HTML mixins and rendering to HTML. The function also accepts an additional argument renderer. To produce LaTeX output:

Finally, here's how you would manually specify extra tokens and a renderer for mistletoe. In the following example, we use HTMLRenderer to render the AST, which adds HTMLBlock and HTMLSpan to the normal parsing process.

Developer's Guide

Note: mistletoe 0.3 significantly simplifies the process of adding your custom tokens, but breaks backwards compatibility. Oh well.

Here's an example to add GitHub-style wiki links to the parsing process, and provide a renderer for this new token.

A new token

GitHub wiki links are span-level tokens, meaning that they reside inline, and don't really look like chunky paragraphs. To write a new span-level token, all we need to do is make a subclass of SpanToken:

mistletoe uses regular expressions to search for span-level tokens in the parsing process. As a refresher, GitHub wiki looks something like this: [[alternative text | target]]. We define a class variable, pattern, that stores the compiled regex:

For spiritual guidance on regexes, refer to xkcd classics. For an actual representation of this author parsing Markdown with regexes, refer to this brilliant meme by Greg Hendershott.

mistletoe's span-level tokenizer will search for our pattern. When it finds a match, it will pass in the first matching group as argument (raw). In our case, this happens to be the entire link with enclosing brackets, so we still need to do some dirty string manipulation:

alt can also contain other span-level tokens. For example, [[*alt*|link]] is a GitHub link with an Emphasis token as its child. To parse child tokens, simply pass it to the super constructor, and save off all the additional attributes we need:

After some cleaning-up, this is what our new token class looks like:

A new renderer

Adding a custom token to the parsing process usually involves a lot of nasty implementation details. Fortunately, mistletoe takes care of most of them for you. Simply pass your custom token class to super().__init__() does the trick:

We then only need to tell mistletoe how to render our new token:

Cleaning up, we have our new renderer class:

Take it for a spin?

For more info, take a look at the base_renderer module in mistletoe. The docstrings might give you a more granular idea of customizing mistletoe to your needs.

Why mistletoe?

For me, the question becomes: why not mistune? My original motivation really has nothing to do with starting a competition. Here's a list of reasons I created mistletoe in the first place:

  • I am interested in a Markdown-to-LaTeX transpiler in Python.
  • I want to write more Python. Specifically, I want to try out some bleeding edge features in Python 3.6, which, in turn, makes me love the language even more.
  • I am stuck at home during summer vacation without an internship, which, in turn, makes me realize how much I love banging out software from scratch, all by myself. Also, global warming keeps me indoors.
  • I have long wanted to write a static site generator, from scratch, by myself. One key piece of the puzzle is my own Markdown parser. 'How hard could it be?' (well, quite a lot harder than I expected.)
  • 'For fun,' says David Beasley.

Here's two things mistune inspired mistletoe to do:

  • Markdown parsers should be fast, and other parser implementations in Python leaves much to be desired.
  • A parser implementation for Markdown does not need to restrict itself to one flavor (or, 'standard') of Markdown.

Here's two things mistletoe does differently from mistune:

  • Per its readme, mistune will always be a single-file script. mistletoe breaks its functionality into modules.
  • mistune, as of now, can only render Markdown into HTML. It is relatively trivial to write a new renderer for mistletoe.
    • This might make mistletoe look a bit closer to MobileDoc, in that it gives simple Markdown additional power to deal with a variety of additional input and output demands.

The implications of these are quite profound, and there's no definite this-is-better-than-that answer. Mistune is near perfect if one wants what it provides: I have used mistune extensively in the past, and had a great experience. If you want more control, however, give mistletoe a try.

Finally, to quote Raymond Hettinger:

If you make something successful, you don't have to make something else unsuccessful.

Messing around in Python and rebuilding tools that I personally use and love is an immensely more rewarding experience than competition.

Copyright & License

  • mistletoe's logo uses artwork by Daniele De Santis, under CC BY 3.0.
  • mistletoe is released under MIT.

We are pleased to announce the reticulate package, a comprehensive set of tools for interoperability between Python and R. The package includes facilities for:

  • Calling Python from R in a variety of ways including R Markdown, sourcing Python scripts, importing Python modules, and using Python interactively within an R session.

  • Translation between R and Python objects (for example, between R and Pandas data frames, or between R matrices and NumPy arrays).

  • Flexible binding to different versions of Python including virtual environments and Conda environments.

Reticulate embeds a Python session within your R session, enabling seamless, high-performance interoperability. If you are an R developer that uses Python for some of your work or a member of data science team that uses both languages, reticulate can dramatically streamline your workflow!

You can install the reticulate pacakge from CRAN as follows:

Read on to learn more about the features of reticulate, or see the reticulate website for detailed documentation on using the package.

Python in R Markdown

The reticulate package includes a Python engine for R Markdown with the following features:

  • Run Python chunks in a single Python session embedded within your R session (shared variables/state between Python chunks)

  • Printing of Python output, including graphical output from matplotlib.

  • Access to objects created within Python chunks from R using the py object (e.g. py$x would access an x variable created within Python from R).

  • Access to objects created within R chunks from Python using the r object (e.g. r.x would access to x variable created within R from Python)

Built in conversion for many Python object types is provided, including NumPy arrays and Pandas data frames. From example, you can use Pandas to read and manipulate data then easily plot the Pandas data frame using ggplot2:

Note that the reticulate Python engine is enabled by default within R Markdown whenever reticulate is installed.

See the R Markdown Python Engine documentation for additional details.

Importing Python modules

You can use the import() function to import any Python module and call it from R. For example, this code imports the Python os module and calls the listdir() function:

Python markdown tab

Functions and other data within Python modules and classes can be accessed via the $ operator (analogous to the way you would interact with an R list, environment, or reference class).

Imported Python modules support code completion and inline help:

See Calling Python from R for additional details on interacting with Python objects from within R.

Sourcing Python scripts

You can source any Python script just as you would source an R script using the source_python() function. For example, if you had the following Python script flights.py:

Then you can source the script and call the read_flights() function as follows:

See the source_python() documentation for additional details on sourcing Python code.

Python REPL

If you want to work with Python interactively you can call the repl_python() function, which provides a Python REPL embedded within your R session. Objects created within the Python REPL can be accessed from R using the py object exported from reticulate. For example:

Enter exit within the Python REPL to return to the R prompt.

Import Markdown Python Code

Note that Python code can also access objects from within the R session using the r object (e.g. r.flights). See the repl_python() documentation for additional details on using the embedded Python REPL.

Type conversions

When calling into Python, R data types are automatically converted to their equivalent Python types. When values are returned from Python to R they are converted back to R types. Types are converted as follows:

RPythonExamples
Single-element vectorScalar1, 1L, TRUE, 'foo'
Multi-element vectorListc(1.0, 2.0, 3.0), c(1L, 2L, 3L)
List of multiple typesTuplelist(1L, TRUE, 'foo')
Named listDictlist(a = 1L, b = 2.0), dict(x = x_data)
Matrix/ArrayNumPy ndarraymatrix(c(1,2,3,4), nrow = 2, ncol = 2)
Data FramePandas DataFramedata.frame(x = c(1,2,3), y = c('a', 'b', 'c'))
FunctionPython functionfunction(x) x + 1
NULL, TRUE, FALSENone, True, FalseNULL, TRUE, FALSE

If a Python object of a custom class is returned then an R reference to that object is returned. You can call methods and access properties of the object just as if it was an instance of an R reference class.

Learning more

Import Markdown Python Tutorial

The reticulate website includes comprehensive documentation on using the package, including the following articles that cover various aspects of using reticulate:

  • Calling Python from R — Describes the various ways to access Python objects from R as well as functions available for more advanced interactions and conversion behavior.

  • R Markdown Python Engine — Provides details on using Python chunks within R Markdown documents, including how call Python code from R chunks and vice-versa.

  • Python Version Configuration — Describes facilities for determining which version of Python is used by reticulate within an R session.

  • Installing Python Packages — Documentation on installing Python packages from PyPI or Conda, and managing package installations using virtualenvs and Conda environments.

  • Using reticulate in an R Package — Guidelines and best practices for using reticulate in an R package.

  • Arrays in R and Python — Advanced discussion of the differences between arrays in R and Python and the implications for conversion and interoperability.

Why reticulate?

From the Wikipedia article on the reticulated python:

Import Markdown Python Example

The reticulated python is a speicies of python found in Southeast Asia. They are the world’s longest snakes and longest reptiles…The specific name, reticulatus, is Latin meaning “net-like”, or reticulated, and is a reference to the complex colour pattern.

From the Merriam-Webster definition of reticulate:

1: resembling a net or network; especially : having veins, fibers, or lines crossing a reticulate leaf. 2: being or involving evolutionary change dependent on genetic recombination involving diverse interbreeding populations.

The package enables you to reticulate Python code into R, creating a new breed of project that weaves together the two languages.

Python Markdown Tutorial

UPDATE:Nov. 27, 2019
Learn more about how R and Python work together in RStudio.