读取excel, 返回列表，列表的每一项是一个子典，包含一项记录
def get_data_from_excel(self, f, colnameindex=0,by_index=0):
"""从excel读取数据, 返回字典形式记录的列表
colnameindex: 表头
"""
try:
data = xlrd.open_workbook(f)
except Exception as e:
return None
sheet = data.sheets()[by_index]
nrows = sheet.nrows #行数
ncols = sheet.ncols #列数
colnames = sheet.row_values(colnameindex) #第一行数据，表头
list =[]
for rownum in range(1,nrows):
row = sheet.row_values(rownum)
if row:
app = {}
for i in range(len(colnames)):
value = row[i]
if type(value) == float and int(value) == value:
value = str(int(value))
app[colnames[i]] = value
list.append(app)
return list
