python data science handbook1

import numpy as np
import matplotlib.pyplot as plt
import seaborn; seaborn.set()

rand = np.random.RandomState(42)
x = rand.rand(10,2) #数组
plt.scatter(x[:,0],x[:,1],s=100) #数组第一列为横坐标，第二列为纵坐标 s=100：散点大小
plt.show()

 any list of dictionaries can be made into a DataFrame

import numpy as np
pd.DataFrame(np.random.rand(3,2),
            columns=['foo','bar'],
            index=['a','b','c'])

import pandas as pd
import numpy as np
class display(object):
    """Display HTML representation of multiple objects"""
    template = """<div style="float: left; padding: 10px;">
    <p style='font-family:"Courier New", Courier, monospace'>{0}</p>{1}
    </div>"""
    def __init__(self, *args):
        self.args = args
        
    def _repr_html_(self):
        return '\n'.join(self.template.format(a, eval(a)._repr_html_())
                         for a in self.args)
    
    def __repr__(self):
        return '\n\n'.join(a + '\n' + repr(eval(a))
                           for a in self.args)
df1 = pd.DataFrame({'employee': ['Bob', 'Jake', 'Lisa', 'Sue'],
                    'group': ['Accounting', 'Engineering', 'Engineering', 'HR']})
df3 = pd.DataFrame({'name': ['Bob', 'Jake', 'Lisa', 'Sue'],
                    'salary': [70000, 80000, 120000, 90000]})
display('df1', 'df3', 'pd.merge(df1, df3, left_on="employee", right_on="name")') #display 允许显示多个结果