python实用库：PrettyTable 学习
PrettyTable说明
PrettyTable 是python中的一个第三方库，可用来生成美观的ASCII格式的表格，十分实用。
以下为官方介绍：
A simple Python library for easily displaying tabular data in a visually appealing ASCII table format.
PrettyTable is a simple Python library designed to make it quick and easy to represent tabular data in visually appealing ASCII tables. It was inspired by the ASCII tables used in the PostgreSQL shell psql. PrettyTable allows for selection of which columns are to be printed, independent alignment of columns (left or right justified or centred) and printing of “sub-tables” by specifying a row range.
PrettyTable安装
使用pip即可十分方便的安装PrettyTable，如下：
pip install PrettyTable
PrettyTable使用示例
github上有PrettyTable的使用说明，链接如下：https://github.com/dprince/python-prettytable
以下是具体的使用示例：
import prettytable as pt
## 按行添加数据
tb = pt.PrettyTable()
tb.field_names = ["City name", "Area", "Population", "Annual Rainfall"]
tb.add_row(["Adelaide",1295, 1158259, 600.5])
tb.add_row(["Brisbane",5905, 1857594, 1146.4])
tb.add_row(["Darwin", 112, 120900, 1714.7])
tb.add_row(["Hobart", 1357, 205556,619.5])
print(tb)
+-----------+------+------------+-----------------+
| City name | Area | Population | Annual Rainfall |
+-----------+------+------------+-----------------+
| Adelaide | 1295 | 1158259 | 600.5 |
| Brisbane | 5905 | 1857594 | 1146.4 |
| Darwin | 112 | 120900 | 1714.7 |
| Hobart | 1357 | 205556 | 619.5 |
+-----------+------+------------+-----------------+
## 按列添加数据
tb.add_column('index',[1,2,3,4])
print(tb)
+-----------+------+------------+-----------------+-------+
| City name | Area | Population | Annual Rainfall | index |
+-----------+------+------------+-----------------+-------+
| Adelaide | 1295 | 1158259 | 600.5 | 1 |
| Brisbane | 5905 | 1857594 | 1146.4 | 2 |
| Darwin | 112 | 120900 | 1714.7 | 3 |
| Hobart | 1357 | 205556 | 619.5 | 4 |
+-----------+------+------------+-----------------+-------+
## 使用不同的输出风格
tb.set_style(pt.MSWORD_FRIENDLY)
print('--- style：MSWORD_FRIENDLY -----')
print(tb)
tb.set_style(pt.PLAIN_COLUMNS)
print('--- style：PLAIN_COLUMNS -----')
print(tb)
## 随机风格，每次不同
tb.set_style(pt.RANDOM)
print('--- style：MSWORD_FRIENDLY -----')
print(tb)
tb.set_style(pt.DEFAULT)
print('--- style：DEFAULT -----')
print(tb)
--- style：MSWORD_FRIENDLY -----
| City name | Area | Population | Annual Rainfall |
| Adelaide | 1295 | 1158259 | 600.5 |
| Brisbane | 5905 | 1857594 | 1146.4 |
| Darwin | 112 | 120900 | 1714.7 |
| Hobart | 1357 | 205556 | 619.5 |
--- style：PLAIN_COLUMNS -----
City name Area Population Annual Rainfall
Adelaide 1295 1158259 600.5
Brisbane 5905 1857594 1146.4
Darwin 112 120900 1714.7
Hobart 1357 205556 619.5
--- style：MSWORD_FRIENDLY -----
@ Adelaide 1295 1158259 600.5 @
@ Brisbane 5905 1857594 1146.4@
@ Darwin 112 120900 1714.7@
@ Hobart 1357 205556 619.5 @
--- style：DEFAULT -----
+-----------+------+------------+-----------------+
| City name | Area | Population | Annual Rainfall |
+-----------+------+------------+-----------------+
| Adelaide | 1295 | 1158259 | 600.5 |
| Brisbane | 5905 | 1857594 | 1146.4 |
| Darwin | 112 | 120900 | 1714.7 |
| Hobart | 1357 | 205556 | 619.5 |
+-----------+------+------------+-----------------+
## 不打印，获取表格字符串
s = tb.get_string()
print(s)
## 可以只获取指定列或行
s = tb.get_string(fields=["City name", "Population"],start=1,end=4)
print(s)
+-----------+------+------------+-----------------+
| City name | Area | Population | Annual Rainfall |
+-----------+------+------------+-----------------+
| Adelaide | 1295 | 1158259 | 600.5 |
| Brisbane | 5905 | 1857594 | 1146.4 |
| Darwin | 112 | 120900 | 1714.7 |
| Hobart | 1357 | 205556 | 619.5 |
+-----------+------+------------+-----------------+
+-----------+------------+
| City name | Population |
+-----------+------------+
| Brisbane | 1857594 |
| Darwin | 120900 |
| Hobart | 205556 |
+-----------+------------+
## 自定义表格输出样式
### 设定左对齐
tb.align = 'l'
### 设定数字输出格式
tb.float_format = "2.2"
### 设定边框连接符为'*"
tb.junction_char = "*"
### 设定排序方式
tb.sortby = "City name"
### 设定左侧不填充空白字符
tb.left_padding_width = 0
print(tb)
*----------*-----*-----------*----------------*
|City name |Area |Population |Annual Rainfall |
*----------*-----*-----------*----------------*
|Adelaide |1295 |1158259 |600.50 |
|Brisbane |5905 |1857594 |1146.40 |
|Darwin |112 |120900 |1714.70 |
|Hobart |1357 |205556 |619.50 |
*----------*-----*-----------*----------------*
## 不显示边框
tb.border = 0
print(tb)
## 修改边框分隔符
tb.set_style(pt.DEFAULT)
tb.horizontal_char = '+'
print(tb)
City name Area Population Annual Rainfall
Adelaide 1295 1158259 600.50
Brisbane 5905 1857594 1146.40
Darwin 112 120900 1714.70
Hobart 1357 205556 619.50
+++++++++++++++++++++++++++++++++++++++++++++++++++
| City name | Area | Population | Annual Rainfall |
+++++++++++++++++++++++++++++++++++++++++++++++++++
| Adelaide | 1295 | 1158259 | 600.50 |
| Brisbane | 5905 | 1857594 | 1146.40 |
| Darwin | 112 | 120900 | 1714.70 |
| Hobart | 1357 | 205556 | 619.50 |
+++++++++++++++++++++++++++++++++++++++++++++++++++
## prettytable也支持输出HTML代码
s = tb.get_html_string()
print(s)
<table>
<tr>
<th>City name</th>
<th>Area</th>
<th>Population</th>
<th>Annual Rainfall</th>
</tr>
<tr>
<td>Adelaide</td>
<td>1295</td>
<td>1158259</td>
<td>600.50</td>
</tr>
<tr>
<td>Brisbane</td>
<td>5905</td>
<td>1857594</td>
<td>1146.40</td>
</tr>
<tr>
<td>Darwin</td>
<td>112</td>
<td>120900</td>
<td>1714.70</td>
</tr>
<tr>
<td>Hobart</td>
<td>1357</td>
<td>205556</td>
<td>619.50</td>
</tr>
</table>
## 使用copy方法复制对象
#tb.set_style(pt.DEFAULT)
tb.horizontal_char = '.'
tb2 = tb.copy()
tb.align = 'l'
tb2.align = 'r'
print(tb)
print(tb2)
## 直接赋值，得到的是索引
tb.horizontal_char = '-'
tb.aliign = 'l'
tb3 = tb
tb3.align = 'r'
print(tb)
print(tb3)
+...........+......+............+.................+
| City name | Area | Population | Annual Rainfall |
+...........+......+............+.................+
| Adelaide | 1295 | 1158259 | 600.50 |
| Brisbane | 5905 | 1857594 | 1146.40 |
| Darwin | 112 | 120900 | 1714.70 |
| Hobart | 1357 | 205556 | 619.50 |
+...........+......+............+.................+
+...........+......+............+.................+
| City name | Area | Population | Annual Rainfall |
+...........+......+............+.................+
| Adelaide | 1295 | 1158259 | 600.50 |
| Brisbane | 5905 | 1857594 | 1146.40 |
| Darwin | 112 | 120900 | 1714.70 |
| Hobart | 1357 | 205556 | 619.50 |
+...........+......+............+.................+
+-----------+------+------------+-----------------+
| City name | Area | Population | Annual Rainfall |
+-----------+------+------------+-----------------+
| Adelaide | 1295 | 1158259 | 600.50 |
| Brisbane | 5905 | 1857594 | 1146.40 |
| Darwin | 112 | 120900 | 1714.70 |
| Hobart | 1357 | 205556 | 619.50 |
+-----------+------+------------+-----------------+
+-----------+------+------------+-----------------+
| City name | Area | Population | Annual Rainfall |
+-----------+------+------------+-----------------+
| Adelaide | 1295 | 1158259 | 600.50 |
| Brisbane | 5905 | 1857594 | 1146.40 |
| Darwin | 112 | 120900 | 1714.70 |
| Hobart | 1357 | 205556 | 619.50 |
+-----------+------+------------+-----------------+