《python从入门到实践》16.2.6 TypeError: object of type ‘int‘ has no len()
#coding:utf-8importpygalimportjsonfromitertoolsimportgroupbydates,months,weeks,weekdays,close=[],[],[],[],[]withopen('btc_close_2017.json','r')asf:btc_data=json.load(f)forbtc_dictinbtc_data:dates.appe