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- #!/usr/bin/env python
- # -*- coding: utf-8 -*-
- '''
- @Auther :liuyuqi.gov@msn.cn
- @Time :2018/7/5 3:08
- @File :test_pandas.py
- '''
- import pandas as pd
- def t1():
- a = [['a', '1.2', '4.2'], ['b', '70', '0.03'], ['x', '5', '0']]
- df = pd.DataFrame(a, columns=list("ABC"))
- print(df.dtypes)
- print(df)
- def t2():
- obj = pd.Series(list('cadaabbcc'))
- uniques = obj.unique()
- print(obj.dtypes)
- print(uniques.shape)
- def t3():
- df = pd.DataFrame()
- df2 = pd.read_csv()
- df3 = pd.Series()
- pd.concat()
- pd.to_datetime()
- pd.merge()
- pd.Timestamp
- def t4():
- df = pd.DataFrame(columns=list("AB"), data=[[1, 2], [3, 4]])
- df["C"] = None
- df["C"][1] = 2
- print(df)
- def t5():
- ser1 = pd.Series([1, 2, 3, 4])
- ser2 = pd.Series(range(4), index=["a", "b", "c", "d"])
- sdata = {'Ohio': 35000, 'Texas': 71000, 'Oregon': 16000, 'Utah': 5000}
- ser3 = pd.Series(sdata)
- # print(ser1)
- print(ser2)
- # 访问Series
- ser2["a"]
- # 所有索引
- ser2.index
- # 所有值
- ser2.values
- def t6():
- df = pd.DataFrame([{"A": "11", "B": "12"}, {"A": "111", "B": "121"}, {"A": "1111", "B": "1211"}])
- print(df)
- print(df.columns.size) # 列数 2
- h, l = df.shape
- print(h, l)
- print(df.iloc[:, 0].size) # 行数 3
- print(df.ix[[0]].index.values[0]) # 索引值 0
- print(df.ix[[0]].values[0][0]) # 第一行第一列的值 11
- print(df.ix[[1]].values[0][1]) # 第二行第二列的值 121
- def t7():
- '''
- 增加一行/一列
- :return:
- '''
- df = pd.DataFrame([{"A": "11", "B": "12"}, {"A": "1111", "B": "1211"}])
- # df.insert(value=list([22, 33]))
- df = df.append(pd.DataFrame([{"A": "1133", "B": "1332"}]))
- print(df)
- # 增加一列:
- df = pd.DataFrame([{"A": "11", "B": "12"}, {"A": "1111", "B": "1211"}])
- df["is"] = False
- print(df)
- def t8():
- # 修改值不能直接引用:df3["mem"][i],而需要df3.loc["mem"][i]
- df = pd.DataFrame([{"A": "11", "B": "12"}, {"A": "1111", "B": "1211"}])
- df["is"] = False
- # df["is"][0] = True
- # df.loc[0][2] = True
- # df.loc[:, "is"] = True
- df.loc[0, "is"] = True
- print(df)
- # DataFrame循环遍历
- def t9():
- df = pd.DataFrame({'a': [1, 2, 3], 'b': [3, 4, 5]})
- for row in df.itertuples():
- print("the index", row.Index)
- print("sum of row", row.a + row.b)
- t9()
- # result = pd.DataFrame(columns=list(["instanceid", "machineid"]), data=list())
- # df = pd.DataFrame({'a': list(range(100)), 'b': [random.random() for i in range(100)]})
- # index = pd.MultiIndex.from_product([list('abcd'), list(range(25))])
- # df.index = index
- # print(df.head())
- # df.loc[('a', -1), :] = None
- # df.tail()
- #
- # data = pd.DataFrame({'a':[1,2,3], 'b':[4,5,6]})
- # data.index = pd.MultiIndex.from_tuples([('a', 1), ('b', 1), ('c', 1)])
- # data
- # new_df = df.append(data)
- # new_df.tail()
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