huatu

import csv
import random
import datetime
import pandas

fn = 'data.csv'
with open(fn,'w') as fp:
    wr = csv.writer(fp)
    wr.writerow(['日期','销量'])
    startDate = datetime.date(2017,1,1)
    for i in range(365):
        amount = 300 + i*5 + random.randrange(100)
        wr.writerow([str(startDate),amount])
        startDate = startDate + datetime.timedelta(days = 1)
f = pandas.read_csv('data.csv',encoding='cp936')
print(f)

plt.figure()
df1 = f[:]
df1[ ‘month’] =df1[‘日期’].map(lambda x:x[:x.rindex(‘-’)])
df1 = df1.groupby(by=‘month’,as_index=False).sum()
df1.plot(x=df1[‘month’],kind=‘bar’)
plt.show()

在这里插入图片描述