python常见 \r \t \n

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import pandas as pd

import numpy as np

import matplotlib.pyplot as plt

from datetime import datetime

%matplotlib inline

data=pd.read_csv(r'C:\Users\TAO\Desktop\python-for-data-analysis-master\examples\spx.csv',index_col=0,parse_dates=True)

data.head()

a=data['SPX'].idxmin(axis=0,skipna=True)

spx=data['SPX']

fig,ax1=plt.subplots(1,1)

data.plot(ax=ax1,style='g--')

crsis_data=[(datetime(2007,10,9),'peak of bull matket'),

            (datetime(2008,3,12),'bear fails'),

            (datetime(2008,9,15),'lehamn bankruptcy')]

for date,label in crsis_data:

    ax1.annotate(label,xy=(date,spx.asof(date)+50),xytext=(date,spx.asof(date)+240),

                arrowprops=dict(facecolor='black',width=3,headwidth=5),

                horizontalalignment='left',verticalalignment='top')

ax1.set_xlim(['1/1/2007','1/1/2011'])

ax1.set_ylim([600,1800])

ax1.set_title('important dates in 2008-2009 financial crisis')

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