Pandas系列-读取csv/txt/excel/mysql数据

本代码演示：

1. pandas读取纯文本文件

• 读取csv文件
• 读取txt文件

1. pandas读取xlsx格式excel文件
2. pandas读取mysql数据表

import pandas as pd

1、读取纯文本文件

1.1 读取CSV，使用默认的标题行、逗号分隔符

fpath = "./datas/ml-latest-small/ratings.csv"

# 使用pd.read_csv读取数据
ratings = pd.read_csv(fpath)

# 查看前几行数据
ratings.head()

.dataframe tbody tr th:only-of-type {
vertical-align: middle;
}

.dataframe tbody tr th {
    vertical-align: top;
}

.dataframe thead th {
    text-align: right;
}

	userId	movieId	rating	timestamp
0	1	1	4.0	964982703
1	1	3	4.0	964981247
2	1	6	4.0	964982224
3	1	47	5.0	964983815
4	1	50	5.0	964982931

# 查看数据的形状，返回(行数、列数)
ratings.shape

(100836, 4)

# 查看列名列表
ratings.columns

Index(['userId', 'movieId', 'rating', 'timestamp'], dtype='object')

# 查看索引列
ratings.index

RangeIndex(start=0, stop=100836, step=1)

# 查看每列的数据类型
ratings.dtypes

userId         int64
movieId        int64
rating       float64
timestamp      int64
dtype: object

1.2 读取txt文件，自己指定分隔符、列名

fpath = "./datas/crazyant/access_pvuv.txt"

pvuv = pd.read_csv(
    fpath,
    sep="\t",
    header=None,
    names=['pdate', 'pv', 'uv']
)

pvuv

.dataframe tbody tr th:only-of-type {
vertical-align: middle;
}

.dataframe tbody tr th {
    vertical-align: top;
}

.dataframe thead th {
    text-align: right;
}

	pdate	pv	uv
0	2019-09-10	139	92
1	2019-09-09	185	153
2	2019-09-08	123	59
3	2019-09-07	65	40
4	2019-09-06	157	98
5	2019-09-05	205	151
6	2019-09-04	196	167
7	2019-09-03	216	176
8	2019-09-02	227	148
9	2019-09-01	105	61

2、读取excel文件

fpath = "./datas/crazyant/access_pvuv.xlsx"
pvuv = pd.read_excel(fpath)

pvuv

.dataframe tbody tr th:only-of-type {
vertical-align: middle;
}

.dataframe tbody tr th {
    vertical-align: top;
}

.dataframe thead th {
    text-align: right;
}

	日期	PV	UV
0	2019-09-10	139	92
1	2019-09-09	185	153
2	2019-09-08	123	59
3	2019-09-07	65	40
4	2019-09-06	157	98
5	2019-09-05	205	151
6	2019-09-04	196	167
7	2019-09-03	216	176
8	2019-09-02	227	148
9	2019-09-01	105	61

3、读取MySQL数据库

import pymysql
conn = pymysql.connect(
        host='127.0.0.1',
        user='root',
        password='12345678',
        database='test',
        charset='utf8'
    )

mysql_page = pd.read_sql("select * from crazyant_pvuv", con=conn)

mysql_page

.dataframe tbody tr th:only-of-type {
vertical-align: middle;
}

.dataframe tbody tr th {
    vertical-align: top;
}

.dataframe thead th {
    text-align: right;
}

	pdate	pv	uv
0	2019-09-10	139	92
1	2019-09-09	185	153
2	2019-09-08	123	59
3	2019-09-07	65	40
4	2019-09-06	157	98
5	2019-09-05	205	151
6	2019-09-04	196	167
7	2019-09-03	216	176
8	2019-09-02	227	148
9	2019-09-01	105	61

本文的代码地址：https://github.com/peiss/ant-learn-pandas