把文件写入到csv文件的程序段如下:
ls=[‘北京’,’上海’,’天津’,’重庆’] f=open("city.csv","w") ______________ f.write(','.join(row)+'\n') f.close()
划线处的代码应该为?( )
for i in ls:
for row in ls:
for i in range(len(ls)):
for row in range(len(ls)):