see https://github.com/jreback/PyDataNYC2015 or http://pandas.pydata.org/pandas-docs/version/0.17.1/style.html#Table-Styles
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%matplotlib inline
import pandas as pd
import numpy as np
import seaborn as sns
pd.options.display.max_rows=12
pd.options.display.width=80
# read a csv
df = pd.read_csv('~/seaborn-data/iris.csv',index_col=False)
# adjust column names
df.columns = df.columns.str.replace('\s+','_').str.lower()
# in pandas 0.17.1 and more : sample and style ...
def color_negative_red(val):
"""
Takes a scalar and returns a string with
the css property `'color: red'` for negative
strings, black otherwise.
"""
color = 'red' if (isinstance(val, (int, float)) and val < 3) else 'black'
return 'color: %s' % color
def highlight_max(s):
'''
highlight the maximum in a Series
'''
is_max = s == s.max()
return ['background-color: yellow' if v else '' for v in is_max]
cm = sns.light_palette("green", as_cmap=True)
(df
.sample (n=7)
.style
.applymap(color_negative_red, subset=pd.IndexSlice[['sepal_width', 'petal_width']])
.bar(subset=['sepal_length', 'petal_length'], color='#7F7FFF')
.background_gradient(subset=['sepal_width', 'petal_width'], cmap=cm)
.apply(highlight_max)
.highlight_null(null_color='red')
)
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# assign = define new temporary columns (like 'mutate' in R language)
(df
.query('sepal_length > 5')
.assign(sepal_ratio = lambda x: x.sepal_width / x.sepal_length,
petal_ratio = lambda x: x.petal_width / x.petal_length)
.plot
.scatter(x='sepal_ratio', y='petal_ratio', figsize=(8,4))
)
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# pipe = like '%>%' in R language
(df
.query('sepal_length > 5')
.assign(sepal_ratio = lambda x: x.sepal_width / x.sepal_length,
petal_ratio = lambda x: x.petal_width / x.petal_length)
.pipe(sns.pairplot, hue='species', size=1.5)
)
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# Pandas interactive
import pandas as pd
import numpy as np
# create a df with random datas
np.random.seed(24)
df = pd.DataFrame({'A': np.linspace(1, 10, 10)})
df = pd.concat([df, pd.DataFrame(np.random.randn(10, 4), columns=list('BCDE'))],
axis=1)
df.iloc[0, 2] = np.nan
# interactive
from IPython.html import widgets
@widgets.interact
def f(h_neg=(0, 359, 1), h_pos=(0, 359), s=(0., 99.9), l=(0., 99.9)):
return (df
.style
.background_gradient(
cmap=sns.palettes.diverging_palette(
h_neg=h_neg, h_pos=h_pos, s=s, l=l, as_cmap=True)
).highlight_null()
)
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from IPython.display import HTML
def hover(hover_color="#ff0f99"):
return dict(selector="tr:hover",
props=[("background-color", "%s" % hover_color)])
styles = [
hover(),
dict(selector="th", props=[("font-size", "150%"),
("text-align", "center")]),
dict(selector="caption", props=[("caption-side", "bottom")])
]
html = (df.style.set_table_styles(styles)
.set_caption("Hover to highlight."))
html
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