A quick hack to make Peewee migrator work with MySQL - Tested against MySQL 5.1.52 on OS X.

mysqlmigrate.py

from peewee import *
from playhouse import migrate

kwargs = dict(
    host    = 'localhost',
    user    = 'root',
    passwd  = '' # The legendary MySQL empty password
)

_db = MySQLDatabase('test', **kwargs)
_db.connect()

class Foo(Model):
    bar = TextField() 

    class Meta:
        database = _db
        db_table = 'foo'

class NewFoo(Foo):
    bar = TextField() 
    baz = CharField(max_length=100, default='')

    class Meta:
        database = _db
        db_table = 'foo'
        

class MySQLMigrator(migrate.Migrator):

    sql_add_column      = 'ALTER TABLE %(table)s ADD COLUMN %(column)s' 
    sql_rename_column   = 'ALTER TABLE %(table)s CHANGE COLUMN %(column)s %(renamed_column)s' 

    # sql_drop_column same as base Migrator class
    # sql_rename_table same as base Migrator class

    sql_null            = 'ALTER TABLE %(table)s MODIFY COLUMN %(column)s'  

    def rename_column(self, model_class, old_name, new_name):
        field = getattr(model_class, old_name)        
        field.db_column = new_name
        self.execute(self.sql_rename_column % {
            'table': self.quote(model_class._meta.db_table),
            'column': old_name,
            'renamed_column': self.compiler.field_sql(field)})

    def set_nullable(self, model_class, field, nullable=False):
        field.null = nullable
        self.execute(self.sql_null % {
            'table': self.quote(model_class._meta.db_table),
            'column': self.compiler.field_sql(field)})
            
    
def run_tests():

    models = (Foo, )
    
    for model in models:
        model.create_table(fail_silently=True)

    migrator = MySQLMigrator(_db)
    with _db.transaction():
        migrator.add_column(NewFoo, NewFoo.baz)
        migrator.set_nullable(NewFoo, NewFoo.baz, nullable=True)
        migrator.rename_column(NewFoo, 'baz', 'qux')
        #migrator.drop_column(NewFoo, 'qux')
        #migrator.rename_table(Foo, 'newfoo')
        
 
if __name__ == '__main__':
    run_tests()