6.2. Import/Export

6.2.1. Reading data

  • with open('filename.csv') - context manager

  • numpy.loadtxt('filename.csv', delimeter=',', unpack=True)

  • csv.DictReader()

  • pandas DataFrame

6.2.2. pandas and matplotlib

  • All of plotting functions expect np.array or np.ma.masked_array as input

  • Classes that are 'array-like' such as pandas data objects and np.matrix may or may not work as intended

  • It is best to convert these to np.array objects prior to plotting

  • Convert a pandas.DataFrame:

    a = pandas.DataFrame(np.random.rand(4,5), columns = list('abcde'))
    a_asndarray = a.values
    

6.2.3. Exporting

agg
cairo
eps
pdf
png
ps
svg
raster graphics
vector graphics

Renderer

Filetypes

Description

AGG

png

raster graphics -- high quality images using the Anti-Grain Geometry engine

PS

ps eps

vector graphics -- Postscript output

PDF

pdf

vector graphics -- Portable Document Format

SVG

svg

vector graphics -- Scalable Vector Graphics

Cairo

png ps pdf svg

raster graphics and vector graphics -- using the Cairo graphics library