pymysql_utils Package

pymysql_utils Module

Created on Sep 24, 2013

@author: paepcke

Modifications:

• Dec 30, 2013: Added closing of connection to close() method

class pymysql_utils.pymysql_utils.MySQLDB(host='127.0.0.1', port=3306, user='root', passwd='', db='mysql')

Bases: object

Shallow interface to MySQL databases. Some niceties nonetheless. The query() method is an iterator. So:

for result in mySqlObj.query('SELECT * FROM foo'):
    print result

bulkInsert(tblName, colNameTuple, valueTupleArray)

Inserts large number of rows into given table. Strategy: write the values to a temp file, then generate a LOAD INFILE LOCAL MySQL command. Execute that command via subprocess.call(). Using a cursor.execute() fails with error ‘LOAD DATA LOCAL is not supported in this MySQL version...’ even though MySQL is set up to allow the op (load-infile=1 for both mysql and mysqld in my.cnf).

Parameters:

• tblName (string) – table into which to insert
• colNameTuple ((str[,str[...]])) – tuple containing column names in proper order, i.e. corresponding to valueTupleArray orders.
• valueTupleArray ([(<anyMySQLCompatibleTypes>[<anyMySQLCompatibleTypes,...]])) – array of n-tuples, which hold the values. Order of values must correspond to order of column names in colNameTuple.

close()

Close all cursors that are currently still open.

createTable(tableName, schema, temporary=False)

Create new table, given its name, and schema. The schema is a dict mappingt column names to column types. Example: {‘col1’ : ‘INT’, ‘col2’ : ‘TEXT’}

Parameters:

• tableName (String) – name of new table
• schema (Dict<String,String>) – dictionary mapping column names to column types

dropTable(tableName)

Delete table safely. No errors

Parameters:tableName (String) – name of table

ensureSQLTyping(colVals)

Given a list of items, return a string that preserves MySQL typing. Example: (10, ‘My Poem’) —> ‘10, “My Poem”’ Note that ‘,’.join(map(str,myList)) won’t work: (10, ‘My Poem’) —> ‘10, My Poem’

Parameters:colVals (<any>) – list of column values destined for a MySQL table

execute(query)

Execute an arbitrary query, including MySQL directives.

Parameters:query (String) – query or directive

executeParameterized(query, params)

Executes arbitrary query that is parameterized as in the Python string format statement. Ex: executeParameterized(‘SELECT %s FROM myTable’, (‘col1’, ‘col3’))

Parameters:

• query (string) – query with parameter placeholder
• params ((<any>)) – actuals for the parameters

insert(tblName, colnameValueDict)

Given a dictionary mapping column names to column values, insert the data into a specified table

Parameters:

• tblName (String) – name of table to insert into
• colnameValueDict (Dict<String,Any>) – mapping of column name to column value

query(queryStr)

Query iterator. Given a query, return one result for each subsequent call.

Parameters:queryStr (String) – query

stringifyList(iterable)

Goes through the iterable. For each element, tries to turn into a string, part of which attempts encoding with the ‘ascii’ codec. Then encountering a unicode char, that char is UTF-8 encoded.

Acts as an iterator! Use like: for element in stringifyList(someList):

print(element)

Parameters:iterable ([<any>]) – mixture of items of any type, including Unicode strings.

truncateTable(tableName)

Delete all table rows. No errors

Parameters:tableName (String) – name of table

update(tblName, colName, newVal, fromCondition=None)

Update one column with a new value.

Parameters:

• tblName (String) – name of table in which update is to occur
• colName (String) – column whose value is to be changed
• newVal (type acceptable to MySQL for the given column) – value acceptable to MySQL for the given column
• fromCondition (String) – optionally condition that selects which rows to update. if None, the named column in all rows are updated to the given value. Syntax must conform to what may be in a MySQL FROM clause (don’t include the ‘FROM’ keyword)

test_pymysql_utils Module

Created on Sep 24, 2013

@author: paepcke

class pymysql_utils.test_pymysql_utils.TestMySQL(methodName='runTest')

Bases: unittest.case.TestCase

To make these unittests work, prepare the local MySQL db as follows:

o CREATE USER unittest; o CREATE DATABASE unittest;

o GRANT SELECT ON unittest.* TO 'unittest'@'localhost‘; o GRANT INSERT ON unittest.* TO 'unittest'@'localhost‘;

o GRANT DROP ON unittest.* TO 'unittest'@'localhost‘; o GRANT CREATE ON unittest.* TO 'unittest'@'localhost‘;

buildSmallDb()

setUp()

tearDown()

testExecuteArbitraryQuery()

testExecuteArbitraryQueryParameterized()

testInsert()

testInsertSeveralColums()

testQueryIterator()

testTruncate()