1.创建数组
index_list = ["a1","a2","a3","a4","a5"]
col_list = ["b1","b2","b3"]
# 注意np.zeros的参数必须是一个,要传行列个数的话,就要把他们作为一个元组传
df = pd.DataFrame(np.zeros((len(index_list),len(col_list))),index = index_list, columns = col_list)
2.读写指定元素
# 修改
df.loc["a3","b3"] = 1
# 查看
print(df.loc["a3","b3"])
print(df.loc["a3",["b3","b2"]])