以编程方式将熊猫数据框转换为降价表

Question

我有一个从数据库生成的Pandas Dataframe，该数据库具有混合编码的数据。例如：

+----+-------------------------+----------+------------+------------------------------------------------+--------------------------------------------------------+--------------+-----------------------+
| ID | path                    | language | date       | longest_sentence                               | shortest_sentence                                      | number_words | readability_consensus |
+----+-------------------------+----------+------------+------------------------------------------------+--------------------------------------------------------+--------------+-----------------------+
| 0  | data/Eng/Sagitarius.txt | Eng      | 2015-09-17 | With administrative experience in the prepa... | I am able to relocate internationally on short not...  | 306          | 11th and 12th grade   |
+----+-------------------------+----------+------------+------------------------------------------------+--------------------------------------------------------+--------------+-----------------------+
| 31 | data/Nor/Høylandet.txt  | Nor      | 2015-07-22 | Høgskolen i Østfold er et eksempel...          | Som skuespiller har jeg både...                        | 253          | 15th and 16th grade   |
+----+-------------------------+----------+------------+------------------------------------------------+--------------------------------------------------------+--------------+-----------------------+

如图所示，英语和挪威语混合在一起（我认为数据库中编码为ISO-8859-1）。我需要以Markdown表的形式获取此Dataframe输出的内容，但不会出现编码问题。我遵循了这个答案（从问题生成Markdown表？）中得到了以下内容：

import sys, sqlite3

db = sqlite3.connect("Applications.db")
df = pd.read_sql_query("SELECT path, language, date, longest_sentence, shortest_sentence, number_words, readability_consensus FROM applications ORDER BY date(date) DESC", db)
db.close()

rows = []
for index, row in df.iterrows():
    items = (row['date'], 
             row['path'], 
             row['language'], 
             row['shortest_sentence'],
             row['longest_sentence'], 
             row['number_words'], 
             row['readability_consensus'])
    rows.append(items)

headings = ['Date', 
            'Path', 
            'Language',
            'Shortest Sentence', 
            'Longest Sentence since', 
            'Words',
            'Grade level']

fields = [0, 1, 2, 3, 4, 5, 6]
align = [('^', '<'), ('^', '^'), ('^', '<'), ('^', '^'), ('^', '>'),
         ('^','^'), ('^','^')]

table(sys.stdout, rows, fields, headings, align)

但是，这会产生UnicodeEncodeError: 'ascii' codec can't encode character u'\xe5' in position 72: ordinal not in range(128)错误。如何将数据框输出为Markdown表？也就是说，出于将该代码存储在文件中以用于编写Markdown文档的目的。我需要输出看起来像这样：

| ID | path                    | language | date       | longest_sentence                               | shortest_sentence                                      | number_words | readability_consensus |
|----|-------------------------|----------|------------|------------------------------------------------|--------------------------------------------------------|--------------|-----------------------|
| 0  | data/Eng/Sagitarius.txt | Eng      | 2015-09-17 | With administrative experience in the prepa... | I am able to relocate internationally on short not...  | 306          | 11th and 12th grade   |
| 31 | data/Nor/Høylandet.txt  | Nor      | 2015-07-22 | Høgskolen i Østfold er et eksempel...          | Som skuespiller har jeg både...                        | 253          | 15th and 16th grade   |

Answer 1

是的，因此，我从Rohit提出的问题Python-编码字符串-瑞典字母）提出了一个建议，扩展了他的答案，并提出了以下内容：

# Enforce UTF-8 encoding
import sys
stdin, stdout = sys.stdin, sys.stdout
reload(sys)
sys.stdin, sys.stdout = stdin, stdout
sys.setdefaultencoding('UTF-8')

# SQLite3 database
import sqlite3
# Pandas: Data structures and data analysis tools
import pandas as pd

# Read database, attach as Pandas dataframe
db = sqlite3.connect("Applications.db")
df = pd.read_sql_query("SELECT path, language, date, shortest_sentence, longest_sentence, number_words, readability_consensus FROM applications ORDER BY date(date) DESC", db)
db.close()
df.columns = ['Path', 'Language', 'Date', 'Shortest Sentence', 'Longest Sentence', 'Words', 'Readability Consensus']

# Parse Dataframe and apply Markdown, then save as 'table.md'
cols = df.columns
df2 = pd.DataFrame([['---','---','---','---','---','---','---']], columns=cols)
df3 = pd.concat([df2, df])
df3.to_csv("table.md", sep="|", index=False)

一个重要的先决条件是shortest_sentence和longest_sentence列不包含不必要的换行符，因为.replace('\n', ' ').replace('\r', '')在提交到SQLite数据库之前对其进行了应用来删除了这些换行符。看来解决方案不是强制执行特定于语言的编码（ISO-8859-1适用于挪威语），而是UTF-8使用该编码代替了default
ASCII。

我在IPython笔记本（Python 2.7.10）中进行了测试，并得到了一个类似于以下的表格（此处固定显示间距）：

| Path                    | Language | Date       | Shortest Sentence                                                                            | Longest Sentence                                                                                                                                                                                                                                         | Words | Readability Consensus |
|-------------------------|----------|------------|----------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------|-----------------------|
| data/Eng/Something1.txt | Eng      | 2015-09-17 | I am able to relocate to London on short notice.                                             | With my administrative experience in the preparation of the structure and content of seminars in various courses, and critiquing academic papers on various levels, I am confident that I can execute the work required as an editorial assistant.       | 306   | 11th and 12th grade   |
| data/Nor/NoeNorrønt.txt | Nor      | 2015-09-17 | Jeg har grundig kjennskap til Microsoft Office og Adobe.                                     | I løpet av studiene har jeg vært salgsmedarbeider for et større konsern, hvor jeg solgte forsikring til studentene og de faglige ansatte ved universitetet i Trønderlag, samt renholdsarbeider i et annet, hvor jeg i en periode var avdelingsansvarlig. | 205   | 18th and 19th grade   |
| data/Nor/Ørret.txt.txt  | Nor      | 2015-09-17 | Jeg håper på positiv tilbakemelding, og møter naturligvis til intervju hvis det er ønskelig. | I løpet av studiene har jeg vært salgsmedarbeider for et større konsern, hvor jeg solgte forsikring til studentene og de faglige ansatte ved universitetet i Trønderlag, samt renholdsarbeider i et annet, hvor jeg i en periode var avdelingsansvarlig. | 160   | 18th and 19th grade   |

因此，Markdown表没有编码问题。