本代码演示:
- pandas读取纯文本文件
- pandas读取xlsx格式excel文件
- 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()
| 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
| 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
| 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
| 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