How to export sqlite to CSV in Python without being formatted as a list?

Question:

Here is what I currently have:

conn = sqlite3.connect(dbfile)
conn.text_factory = str ## my current (failed) attempt to resolve this
cur = conn.cursor()
data = cur.execute("SELECT * FROM mytable")

f = open('output.csv', 'w')
print >> f, "Column1, Column2, Column3, Etc."
for row in data:
  print >> f, row
f.close()

It creates a CSV file with output that looks like this:

Column1, Column2, Column3, Etc.
(1, u'2011-05-05 23:42:29',298776684,1448052234,463564768,-1130996322, None, u'2011-05-06 04:44:41')

I don’t want the rows to be in parentheses nor have quotes nor the ‘u’ before strings. How do I get it to write the rows to csv without all of this? Thanks,

Asked By: Dan

||

Answers:

What you’re currently doing is printing out the python string representation of a tuple, i.e. the return value of str(row). That includes the quotes and ‘u’s and parentheses and so on.

Instead, you want the data formatted properly for a CSV file. Well, try the csv module. It knows how to format things for CSV files, unsurprisingly enough.

with open('output.csv', 'w', newline='') as f:
    writer = csv.writer(f)
    writer.writerow(['Column 1', 'Column 2', ...])
    writer.writerows(data)

The newline='' is apparently needed for correct escaping of newlines inside quoted fields.

Answered By: Danica

Converting an sqlite database table to csv file can also be done directly using sqlite3 tools:

>sqlite3 c:/sqlite/chinook.db
sqlite> .headers on
sqlite> .mode csv
sqlite> .output data.csv
sqlite> SELECT customerid,
   ...>        firstname,
   ...>        lastname,
   ...>        company
   ...>   FROM customers;
sqlite> .quit

The above sqlite3 commands will will create a csv file called data.csv in your current directory (of course this file can be named whatever you choose). More details are available here: http://www.sqlitetutorial.net/sqlite-export-csv/

Answered By: Hula_Zell

my version that works without issues with just a couple of lines.

import pandas as pd

conn = sqlite3.connect(db_file, isolation_level=None,
                       detect_types=sqlite3.PARSE_COLNAMES)
db_df = pd.read_sql_query("SELECT * FROM error_log", conn)
db_df.to_csv('database.csv', index=False)

If you want a table separated file, change the .csv extension to .tsv and add this sep='t'

Answered By: Gopinath S

I used a silly but easier one if only one table exists!

First I converted the database to a Pandas DataFrame

conn = sqlite3.connect(database file)
df = pd.read_sql_query("select * from TABLE", conn)

Then convert df to a CSV file

df.to_csv(r'...test_file.csv')

So a CSV file is creating under name of test_file.CSV

Answered By: MJ Hessami
Categories: questions Tags: , , ,
Answers are sorted by their score. The answer accepted by the question owner as the best is marked with
at the top-right corner.