Python and Plone User Group Meeting, Munich, 6/2/2015
# ## From Newton's notebook
#
# ### From Newton to a modern notebook
# * *explanations*
# text which may be structured and contain formulae
# * *mathematical manipulations*
# code and results
# * *diagrams*
# graphical representations and multimedia objects
# * *representation*
# HTML, PDF, …
# ### Applications of notebooks
# * Development of small Python scripts
# example: optimization for Cython
# * Documentation
# example: data analysis
# * Teaching material
# examples: lectures, programming course
# * Textbooks
# examples: [nbviewer.ipython.org](http://nbviewer.ipython.org/), books section
# * Presentation
# with notebook extension RISE by Damián Avila
# * …
# ## Python
#
# * interpreted language
# * relatively easy to learn
# * "Python comes with batteries included"
# * SciPy stack: NumPy, SciPy, Matplotlib, pandas,...
# ## IPython - the improved Python shell
#
# * 2001: Fernando Pérez launches the IPython project.
# * December 2011: IPython 0.12 introduces the **IPython notebook**.
# * 2013–2014: The development of IPython is supported by the Alfred P. Sloan foundation with 1.15 M`$`.
# * August 2013: Microsoft supports the development of IPython with 100.000`$`.
# * February, 27 2015: Release of Version 3.0.
# * May 2015: IPython is part of the Horizon 2020 project [OpenDreamKit](http://opendreamkit.org)
# * Next milestone: The language agnostic part moves to the [Jupyter project](http://jupyter.org).
# ### IPython sources
# Homepage: [ipython.org](http://ipython.org)
# Repository: [github.com/ipython/ipython](http://github.com/ipython/ipython)
# Mailing list: ipython-dev@scipy.org
#
# ### Debian and Ubuntu packages:
# `ipython-notebook` / `ipython3-notebook`
# ipython 1.2.1: Debian wheezy-backports, Ubuntu 14.04LTS
# ipython 2.3.0: Debian jessie, Ubuntu 15.04
# ipython 3.1.0: [pypi.python.org](http://pypi.python.org)
#
# ### Installation within a virtual environment
# `pip install "ipython[notebook]"`
#
# see also: [ipython.org/install.html](http://ipython.org/install.html)
#
#
#
# ## Notebook cells
#
# * Code cells
# * Text cells
# * Raw cells for interpretation by `NBConvert`
# ### Working with notebook cells
#
# A selected notebook cell is in one of two modes:
#
# * command mode = black frame
# * input mode = green frame and pencil symbol in header
# * switch to input mode: `ENTER` or doubleclick
# * switch to command mode: `ESC` or `CTRL-M`
# ### Useful keyboard shortcuts
# * `SHIFT-ENTER`, `CTRL-ENTER`: execute the selected cell
# * `ALT-ENTER`: execute the selected cell and open a new one
# * `A`: insert a new cell above the present cell
# * `B`: insert a new cell below the present cell
# * `D,D`: delete the selected cell
# * `M`: define selected cell as markdown cell
# * `H`: display all keyboard shortcuts
# ### Code cells
# In[ ]:
for n in range(3):
print("The IPython notebook is great.")
# Code cells are numbered in the sequence in which they are executed.
# Magics can be used to insert and execute code not written in Python, e.g. HTML:
# In[ ]:
get_ipython().run_cell_magic('html', '', ' \n')
# ### Text cells
# Formatting can be down in markdown and HTML.
#
# Examples:
# * *text in italics* oder _text in italics_
# * **text in bold** oder __text in bold__
# * `code`
# * emphasized text
#
#
# ### Mathematical typesetting
# LaTeX syntax can be used in text cells to display mathematical symbols like $\ddot x$ or entire formulae:
# $$\mathcal{L}\{f(t)\} = \int_0^\infty\text{d}z\text{e}^{-zt}f(t)$$
#
# Mathematics is displayed with MathJax ([www.mathjax.org](http://www.mathjax.org))
# and requires either an internet connection or a local installation. Instructions for a local installation can be obtained as follows:
# In[ ]:
from IPython.external import mathjax
get_ipython().run_line_magic('pinfo', 'mathjax')
# ## Selected features of the IPython shell
# ### Help
# In[ ]:
import numpy as np
get_ipython().run_line_magic('pinfo', 'np.tensordot')
# Description including code (if available)
# In[ ]:
get_ipython().run_line_magic('pinfo2', 'np.tensordot')
# Code completion with `TAB`
# In[ ]:
np.ALLOW_THREADS
# ### Reference to earlier results
# In[ ]:
2**3
# In[ ]:
_-8
# In[ ]:
__**2
# ### Access to all earlier input and output
# In[ ]:
In, Out
# ### Magics in IPython
# In[ ]:
get_ipython().run_line_magic('lsmagic', '')
# Quick reference
# In[ ]:
get_ipython().run_line_magic('quickref', '')
# Timing of code execution
# In[ ]:
get_ipython().run_line_magic('timeit', '2.5**100')
# In[ ]:
import math
# In[ ]:
get_ipython().run_cell_magic('timeit', '', 'result = []\nnmax = 100000\ndx = 0.001\nfor n in range(nmax):\n result.append(math.sin(n*dx))\n')
# In[ ]:
get_ipython().run_cell_magic('timeit', '', 'nmax = 100000\ndx = 0.001\nx = np.arange(nmax)*dx\nresult = np.sin(x)\n')
# ## Extended representations
# IPython allows for the representation of objects in formats as different as
#
# * HTML
# * Markdown
# * SVG
# * PNG
# * JPEG
# * LaTeX
# In[ ]:
from IPython.display import Image
Image("./images/ipython_logo.png")
# In[ ]:
from IPython.display import HTML
HTML('')
# Even the embedding of audio and video files is possible.
# In[ ]:
from IPython.display import YouTubeVideo
YouTubeVideo('F4rFuIb1Ie4')
# Python allows for a textual representation of objects by means of the ``__repr__`` method.
#
# example:
# In[ ]:
class MyObject(object):
def __init__(self, obj):
self.obj = obj
def __repr__(self):
return ">>> {0!r} / {0!s} <<<".format(self.obj)
x = MyObject('Python')
print(x)
# A rich representation of objects is possible in the IPython notebook provided the corresponding methods are defined:
#
# * `_repr_pretty_`
# * `_repr_html_`
# * `_repr_markdown_`
# * `_repr_latex`
# * `_repr_svg_`
# * `_repr_json_`
# * `_repr_javascript_`
# * `_repr_png_`
# * `_repr_jpeg_`
#
# Note: In contrast to `__repr__` only one underscore is used.
# In[ ]:
class RGBColor(object):
def __init__(self, r, g, b):
self.colordict = {"r": r, "g":g, "b": b}
def _repr_svg_(self):
return ''''''.format(**self.colordict)
c = RGBColor(205, 128, 255)
c
# In[ ]:
from fractions import Fraction
class MyFraction(Fraction):
def _repr_html_(self):
return "%s⁄%s" % (self.numerator,
self.denominator)
def _repr_latex_(self):
return r"$\frac{%s}{%s}$" % (self.numerator, self.denominator)
def __add__(a, b):
"""a + b"""
return MyFraction(a.numerator * b.denominator +
b.numerator * a.denominator,
a.denominator * b.denominator)
MyFraction(12, 345)+MyFraction(67, 89)
# In[ ]:
from IPython.display import display_latex
display_latex(MyFraction(12, 345)+MyFraction(67, 89))
# ## Interaction with widgets
# In[ ]:
from IPython.html.widgets import interact
# In[ ]:
@interact(x=(0., 10.), y=(0, 10))
def power(y, x=2):
print(x**y)
# #### Data types and their associated widgets
#
# String (`str`, `unicode`) → Text
# Dictionary (`dict`) → Dropdown
# Boolean variable (`bool`) → Checkbox
# Float (`float`) → FloatSlider
# Integer (`int`) → IntSlider
# In[ ]:
@interact(x=(0, 5),
text="Python is great!!!")
def f(text, x=0):
for _ in range(x):
print(text)
# In[ ]:
from IPython.html import widgets
import numpy as np
import matplotlib.pyplot as plt
get_ipython().run_line_magic('matplotlib', 'inline')
# otherwise matplotlib graphs will be displayed in an external window
@interact(harmonics=widgets.IntSlider(min=1, max=10,
description='Number of harmonics',
padding='2ex'),
function=widgets.RadioButtons(options=("square",
"sawtooth",
"triangle"),
description='Function')
)
def f(harmonics, function):
params = {"square": {"sign":1, "stepsize": 2, "func": np.sin, "power": 1},
"sawtooth": {"sign": -1, "stepsize": 1, "func": np.sin, "power": 1},
"triangle": {"sign": 1, "stepsize": 2, "func": np.cos, "power": 2}
}
p = params[function]
xvals, nvals = np.ogrid[-2*np.pi:2*np.pi:100j, 1:harmonics+1:p["stepsize"]]
yvals = np.sum(p["sign"]**nvals*p["func"](nvals*xvals)/nvals**p["power"],
axis=1)
plt.plot(xvals, yvals)
# See also the tutorial by Cyrille Rossant at https://github.com/rossant/euroscipy2014.
# ## Transformation of IPython-Notebooks to various output formats
# `ipython notebook --to` *format* *notebook filename*
#
# Output formats:
# * HTML for presentation with `reveal.js`
# * LaTeX, PDF
# * Markdown
# * Restructured text
# * Python
#
#
# Static representation of notebooks: [nbviewer.ipython.org](http://nbviewer.ipython.org "nbviewer")
# ### From Newton to a modern notebook
# * *explanations*
# text which may be structured and contain formulae
# * *mathematical manipulations*
# code and results
# * *diagrams*
# graphical representations and multimedia objects
# * *representation*
# HTML, PDF, …
# ### Applications of notebooks
# * Development of small Python scripts
# example: optimization for Cython
# * Documentation
# example: data analysis
# * Teaching material
# examples: lectures, programming course
# * Textbooks
# examples: [nbviewer.ipython.org](http://nbviewer.ipython.org/), books section
# * Presentation
# with notebook extension RISE by Damián Avila
# * …
# ## Python
#
# * interpreted language
# * relatively easy to learn
# * "Python comes with batteries included"
# * SciPy stack: NumPy, SciPy, Matplotlib, pandas,...
# ## IPython - the improved Python shell
#
# * 2001: Fernando Pérez launches the IPython project.
# * December 2011: IPython 0.12 introduces the **IPython notebook**.
# * 2013–2014: The development of IPython is supported by the Alfred P. Sloan foundation with 1.15 M`$`.
# * August 2013: Microsoft supports the development of IPython with 100.000`$`.
# * February, 27 2015: Release of Version 3.0.
# * May 2015: IPython is part of the Horizon 2020 project [OpenDreamKit](http://opendreamkit.org)
# * Next milestone: The language agnostic part moves to the [Jupyter project](http://jupyter.org).
# ### IPython sources
# Homepage: [ipython.org](http://ipython.org)
# Repository: [github.com/ipython/ipython](http://github.com/ipython/ipython)
# Mailing list: ipython-dev@scipy.org
#
# ### Debian and Ubuntu packages:
# `ipython-notebook` / `ipython3-notebook`
# ipython 1.2.1: Debian wheezy-backports, Ubuntu 14.04LTS
# ipython 2.3.0: Debian jessie, Ubuntu 15.04
# ipython 3.1.0: [pypi.python.org](http://pypi.python.org)
#
# ### Installation within a virtual environment
# `pip install "ipython[notebook]"`
#
# see also: [ipython.org/install.html](http://ipython.org/install.html)
#
#
#
# ## Notebook cells
#
# * Code cells
# * Text cells
# * Raw cells for interpretation by `NBConvert`
# ### Working with notebook cells
#
# A selected notebook cell is in one of two modes:
#
# * command mode = black frame
# * input mode = green frame and pencil symbol in header
# * switch to input mode: `ENTER` or doubleclick
# * switch to command mode: `ESC` or `CTRL-M`
# ### Useful keyboard shortcuts
# * `SHIFT-ENTER`, `CTRL-ENTER`: execute the selected cell
# * `ALT-ENTER`: execute the selected cell and open a new one
# * `A`: insert a new cell above the present cell
# * `B`: insert a new cell below the present cell
# * `D,D`: delete the selected cell
# * `M`: define selected cell as markdown cell
# * `H`: display all keyboard shortcuts
# ### Code cells
# In[ ]:
for n in range(3):
print("The IPython notebook is great.")
# Code cells are numbered in the sequence in which they are executed.
# Magics can be used to insert and execute code not written in Python, e.g. HTML:
# In[ ]:
get_ipython().run_cell_magic('html', '', ' \n')
# ### Text cells
# Formatting can be down in markdown and HTML.
#
# Examples:
# * *text in italics* oder _text in italics_
# * **text in bold** oder __text in bold__
# * `code`
# * emphasized text
#
#
# ### Mathematical typesetting
# LaTeX syntax can be used in text cells to display mathematical symbols like $\ddot x$ or entire formulae:
# $$\mathcal{L}\{f(t)\} = \int_0^\infty\text{d}z\text{e}^{-zt}f(t)$$
#
# Mathematics is displayed with MathJax ([www.mathjax.org](http://www.mathjax.org))
# and requires either an internet connection or a local installation. Instructions for a local installation can be obtained as follows:
# In[ ]:
from IPython.external import mathjax
get_ipython().run_line_magic('pinfo', 'mathjax')
# ## Selected features of the IPython shell
# ### Help
# In[ ]:
import numpy as np
get_ipython().run_line_magic('pinfo', 'np.tensordot')
# Description including code (if available)
# In[ ]:
get_ipython().run_line_magic('pinfo2', 'np.tensordot')
# Code completion with `TAB`
# In[ ]:
np.ALLOW_THREADS
# ### Reference to earlier results
# In[ ]:
2**3
# In[ ]:
_-8
# In[ ]:
__**2
# ### Access to all earlier input and output
# In[ ]:
In, Out
# ### Magics in IPython
# In[ ]:
get_ipython().run_line_magic('lsmagic', '')
# Quick reference
# In[ ]:
get_ipython().run_line_magic('quickref', '')
# Timing of code execution
# In[ ]:
get_ipython().run_line_magic('timeit', '2.5**100')
# In[ ]:
import math
# In[ ]:
get_ipython().run_cell_magic('timeit', '', 'result = []\nnmax = 100000\ndx = 0.001\nfor n in range(nmax):\n result.append(math.sin(n*dx))\n')
# In[ ]:
get_ipython().run_cell_magic('timeit', '', 'nmax = 100000\ndx = 0.001\nx = np.arange(nmax)*dx\nresult = np.sin(x)\n')
# ## Extended representations
# IPython allows for the representation of objects in formats as different as
#
# * HTML
# * Markdown
# * SVG
# * PNG
# * JPEG
# * LaTeX
# In[ ]:
from IPython.display import Image
Image("./images/ipython_logo.png")
# In[ ]:
from IPython.display import HTML
HTML('')
# Even the embedding of audio and video files is possible.
# In[ ]:
from IPython.display import YouTubeVideo
YouTubeVideo('F4rFuIb1Ie4')
# Python allows for a textual representation of objects by means of the ``__repr__`` method.
#
# example:
# In[ ]:
class MyObject(object):
def __init__(self, obj):
self.obj = obj
def __repr__(self):
return ">>> {0!r} / {0!s} <<<".format(self.obj)
x = MyObject('Python')
print(x)
# A rich representation of objects is possible in the IPython notebook provided the corresponding methods are defined:
#
# * `_repr_pretty_`
# * `_repr_html_`
# * `_repr_markdown_`
# * `_repr_latex`
# * `_repr_svg_`
# * `_repr_json_`
# * `_repr_javascript_`
# * `_repr_png_`
# * `_repr_jpeg_`
#
# Note: In contrast to `__repr__` only one underscore is used.
# In[ ]:
class RGBColor(object):
def __init__(self, r, g, b):
self.colordict = {"r": r, "g":g, "b": b}
def _repr_svg_(self):
return ''''''.format(**self.colordict)
c = RGBColor(205, 128, 255)
c
# In[ ]:
from fractions import Fraction
class MyFraction(Fraction):
def _repr_html_(self):
return "%s⁄%s" % (self.numerator,
self.denominator)
def _repr_latex_(self):
return r"$\frac{%s}{%s}$" % (self.numerator, self.denominator)
def __add__(a, b):
"""a + b"""
return MyFraction(a.numerator * b.denominator +
b.numerator * a.denominator,
a.denominator * b.denominator)
MyFraction(12, 345)+MyFraction(67, 89)
# In[ ]:
from IPython.display import display_latex
display_latex(MyFraction(12, 345)+MyFraction(67, 89))
# ## Interaction with widgets
# In[ ]:
from IPython.html.widgets import interact
# In[ ]:
@interact(x=(0., 10.), y=(0, 10))
def power(y, x=2):
print(x**y)
# #### Data types and their associated widgets
#
# String (`str`, `unicode`) → Text
# Dictionary (`dict`) → Dropdown
# Boolean variable (`bool`) → Checkbox
# Float (`float`) → FloatSlider
# Integer (`int`) → IntSlider
# In[ ]:
@interact(x=(0, 5),
text="Python is great!!!")
def f(text, x=0):
for _ in range(x):
print(text)
# In[ ]:
from IPython.html import widgets
import numpy as np
import matplotlib.pyplot as plt
get_ipython().run_line_magic('matplotlib', 'inline')
# otherwise matplotlib graphs will be displayed in an external window
@interact(harmonics=widgets.IntSlider(min=1, max=10,
description='Number of harmonics',
padding='2ex'),
function=widgets.RadioButtons(options=("square",
"sawtooth",
"triangle"),
description='Function')
)
def f(harmonics, function):
params = {"square": {"sign":1, "stepsize": 2, "func": np.sin, "power": 1},
"sawtooth": {"sign": -1, "stepsize": 1, "func": np.sin, "power": 1},
"triangle": {"sign": 1, "stepsize": 2, "func": np.cos, "power": 2}
}
p = params[function]
xvals, nvals = np.ogrid[-2*np.pi:2*np.pi:100j, 1:harmonics+1:p["stepsize"]]
yvals = np.sum(p["sign"]**nvals*p["func"](nvals*xvals)/nvals**p["power"],
axis=1)
plt.plot(xvals, yvals)
# See also the tutorial by Cyrille Rossant at https://github.com/rossant/euroscipy2014.
# ## Transformation of IPython-Notebooks to various output formats
# `ipython notebook --to` *format* *notebook filename*
#
# Output formats:
# * HTML for presentation with `reveal.js`
# * LaTeX, PDF
# * Markdown
# * Restructured text
# * Python
#
#
# Static representation of notebooks: [nbviewer.ipython.org](http://nbviewer.ipython.org "nbviewer")