Jupyter

Jupyter notebook is formerly known as IPython notebook, it is a tool that helps you create readable analyses. Jupyter works with python kernel by default, but it also supports many other kernels.

Keyboard shortcurts

  • Cmd + Shift + P: open command palette

Set environment variables

# The line below sets the environment
# variable OMP_NUM_THREADS
%env OMP_NUM_THREADS=4
env: OMP_NUM_THREADS=4

Execute python code

# this will execute and show the output from
# all code cells of the specified notebook
%run ./helloworld.py
Hello, TensorFlow!
[ 2.  4.  6.]
[[  2.   4.   6.]
 [  8.  10.  12.]]

load code to current cell

# %load helloworld.py
#!/usr/bin/env python
import tensorflow as tf

# Create a Constant op
# The op is added as a node to the default graph.
#
# The value returned by the constructor represents the output
# of the Constant op.
hello = tf.constant('Hello, TensorFlow!')
x = tf.placeholder("float", 3)
a = tf.placeholder("float", shape=[None, 3])

y = x*2
b = a*2

# Start tf session
sess = tf.Session()
sess.run(tf.initialize_all_tables())

print sess.run(hello)
print sess.run(y, feed_dict={x:[1,2,3]})
print sess.run(b, feed_dict={a:[[1,2,3], [4,5,6]]})

sess.close()

Pass variables between notebooks

data = 'this is the string I want to pass to different notebook'
%store data
del data # This has deleted the variable

%store -r data
print(data)
Stored 'data' (str)
this is the string I want to pass to different notebook

Plot inline

%matplotlib inline

from matplotlib import pyplot as plt
import numpy

x = numpy.linspace(0, 1, 1000)**1.5;
plt.hist(x);

png

Latex forumlas

P(AB)=P(BA)P(A)P(B) P(A \mid B) = \frac{P(B \mid A) \, P(A)}{P(B)}

Writing functions in other languages

!pip install cython fortran-magic

%load_ext Cython

%%cython
def myltiply_by_2(float x):
    return 2.0 * x

myltiply_by_2(23.)

Other jupyter magic

  • %matplotlib inline: plot inline.
  • %who: List all variables of global scope.
  • %%time and %timeit: timing the code.
  • %lsmagic: list magic commands
  • %%writefile pythoncode.py: export contents of the cell to pythoncode.py
  • %pycat pythoncode.py: show the contents of an external script
  • %prun: Show how much time your program spent in each function.
  • %pdb: debugging with pdb.
  • !pip install numpy: executing shell commands.
  • %%bash, %%HTML, %%ruby, %%R: swith to other kernel.

Jupyter-contrib extensions

!pip install https://github.com/ipython-contrib/jupyter_contrib_nbextensions/tarball/master
!pip install jupyter_nbextensions_configurator
!jupyter contrib nbextension install --user
!jupyter nbextensions_configurator enable --user

Create a presentation

!pip install RISE

jupyter-nbextension install rise --py --sys-prefix
jupyter-nbextension enable rise --py --sys-prefix

Jupyter themes

pip install --upgrade jupyterthemes
jt -T -N -t grade3
© Pengfei Ni all right reserved,powered by GitbookUpdated at 2017-03-30 07:27:29

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