This repository holds the material from a Python course that was held at Mullard Space Science Laboratory on 1st of October, 2012.

The presentation view graphs are available in PDF and Keynote format and can be found in the presentation folder.

The iPython Notebooks are available from the notebook folder. Please note that you will most likely need version 0.13 or a newer to run the examples.

The following items were discussed:

• Background Information and Tools

  • Why Python?
  • Syntax, basic types, standard libraries, exception handling, etc.
  • Interactive computing (ipython)
  • How to write documentation within the code (Sphinx)
  • Development tools and version control (PyCharm & GIT)

• Numerical Arrays

  • 1D and N-D arrays, arithmetics, masked arrays, manipulations, and generating random data (NumPy & numexpr)

• Astronomy Specific Packages

  • PyFITS & PyWCS:

    • Reading, writing, and generating FITS tables and image arrays
    • World Coordinate Systems; calculating the RA and DEC of pixels in your image

  • PyRAF:

    • How to call IRAF from Python

• Data Access and Processing:

  • Reading in an ascii file and pickled data (NumPy, cPickle)
  • Creating an sqlite database and querying it (real-world example using SDSS data)

• Scientific analysis:

  • optimisation, fitting, interpolation, root finding, and statistics and distributions (SciPy, statsmodels)

• Generating publication quality plots:

  • 2D plotting (matplotlib)
  • Astronomy specific plotting e.g. different projections (Kapteyn)

• Image manipulation:

  • Smoothing and convolving (SciPy)
  • Object detection, segmentation, and edge detection (scikits-image)

• Speeding things up:

  • Parallel programming with multiprocessing
  • Calling Fortran code from Python

• Machine learning:

  • Principal Component Analysis
  • Supervised Learning, Clustering, etc. (scikits-learn)

A small selection of 3rd party packages I have found extremely useful:

• NumPy: a powerful N-dimensional array object, tools for integrating C/C++ and Fortran code, and useful linear algebra, Fourier transform, and random number capabilities.
• SciPy: open-source software for mathematics, science, and engineering.
• matplotlib: a python 2D plotting library which produces publication quality figures in a variety of hardcopy formats and interactive environments.
• PyFITS: provides an interface to FITS files.
• astropy:a common effort to develop a single core package for Astronomy (contains e.g. PyFITS, PyWCS, vo, asciitable…)
• Kapteyn: provide tools for the development of astronomical applications (WCS projections, non-linear least sq fitting, etc.)
• PyWCS: provides transformations following the SIP conventions and the core WCS functionality.
• SymPy: a Python library for symbolic mathematics
• scikits:add-on toolkits that complement SciPy (sub packages like image, learn, time series, etc.)
• RPy2: provides a low-level interface to R and R-like structures and functions.
• PyMC: Markov Chain Monte Carlo sampling toolkit.
• emcee: implementation of Goodman & Weare’s Affine Invariant Markov Chain Monte Carlo Ensemble sampler.
• PyIDL: python bindings to IDL.
• APLpy: the Astronomical Plotting Library in Python.
• astLib: a set of Python modules that provides e.g. coordinate conversions, manipulating WCS info, perform calculations on SEDs, etc.
• statsmodels: allows users to explore data, estimate statistical models, and perform statistical tests.
• MySQLdb: an thread-compatible interface to the MySQL database server.
• Python Imaging Library (PIL): adds image processing capabilities.
• PyCUDA: gives an easy access to Nvidia‘s CUDA parallel computation API.
• yt-project: provides a consistent, cross-code interface to analyzing and visualizing astrophysical simulation data from a physical perspective.
• mplstereonet: provides lower-hemisphere equal-area and equal-angle stereonets for matplotlib.
• h5py: a general-purpose interface to the Hierarchical Data Format library, version 5.
• Patsy: describing statistical models and building design matrices
• SfePy: software for solving systems of coupled partial differential equations by the finite element method.
• SQLAlchemy: an SQL toolkit and Object Relational Mapper that gives application developers the full power and flexibility of SQL.
• Tkinter: de-facto standard GUI (Graphical User Interface) package.
• PyGtk: a set of Python bindings to the GTK Toolkit.
• PyQt: bindings for the Qt cross-platform GUI/XML/SQL C++ framework.
• Mutagen: a module to handle audio metadata (MP3, Ogg FLAC, etc.).
• Django: a high-level Python Web framework that encourages rapid development and clean, pragmatic design.
• numexpr: evaluates multiple-operator array expressions many times faster than NumPy can.
• PyPy: a fast, compliant alternative implementation of the Python language (2.7.2).
• ATpy: a high-level Python package providing a way to manipulate tables of astronomical data in a uniform way.