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Showing posts from December, 2015

csv to list in python

This is dead simple way to read a csv file and feed the data into a Python list:

import csv
with open('file.csv', 'rb') as f:
    reader = csv.reader(f)
    your_list = list(reader)

print your_list # [['This is the first line', 'Line1'],# ['This is the second line', 'Line2'],# ['This is the third line', 'Line3']]
Reference:http://stackoverflow.com/questions/24662571/python-import-csv-to-list

Duplicate entry error with the Django's User Profile model

I wrote a User Profile model which extends the Django's User authentication model as following:

class TeacherProfile(models.Model):
    user = models.OneToOneField(User, related_name="teacher_profile", \
                        related_query_name="profile")
    teacher_number = models.CharField(max_length=255, blank=True, null=True) # Office
    desc = models.CharField(max_length=255, blank=True, null=True) # Description
    title = models.CharField(max_length=255, blank=True, null=True)
    school = models.ForeignKey('School', null=True, 
                        related_name="steacher_profiles",
                        related_query_name="steacher_profile",
            )

    def __unicode__(self):
      return '<TeacherProfile %s>' % self.teacher_number

# auto create teacher profile the first time student log-in
def create_teacher_profile(sender, instance, created, **kwargs):
    if created:
        new_profile = TeacherProfile.object…

Sort Python dictionaries by key

Even though dictionaries in Python are unordered, we can use this following technique to sort the dictionaries:


>>> import collections

>>> d = {2:3, 1:89, 4:5, 3:0}

>>> od = collections.OrderedDict(sorted(d.items()))

>>> od
OrderedDict([(1, 89), (2, 3), (3, 0), (4, 5)])

And the best thing is we can still using that collection just like our old dictionary:

>> od[1]
89

>>> for k, v in od.iteritems(): print k, v
1  89
2  3
3  0
4  5

Note: the only difference is that we use iteritems() instead of items(). But it will be the same in python 3 (items())

References:http://stackoverflow.com/questions/9001509/how-can-i-sort-a-dictionary-by-key

For me

Another quote of the day

“A single person is missing for you, and the whole world is empty.”

― Joan Didion, The Year of Magical Thinking

Quote of the day

"One who wants to wear the crown, bears the crown."

~"The Heirs"

Question of the day

"What type of crown are you trying to wear?  Was it wealth, fame or love?"

~"The Heirs"

Django celery task's timezone error

For some reason when I access the celery's tasks page in the Django's admin (.../djcelery/taskstate/), I got this error:

Database returned an invalid value in QuerySet.datetimes(). Are time zone definitions for your database and pytz installed?

I have to do the following to get rid of the error:

1. Uncomment these settings:

# CELERY_TIMEZONE = 'UTC'
# CELERY_ENABLE_UTC = True

2. Add this under mysqld section in /etc/mysql/my.cnf:

default-time-zone = "+07:00"

3. Run the following command (without sudo):

$ mysql_tzinfo_to_sql /usr/share/zoneinfo | mysql -u root -p  mysql

4. Restart mysql:

$ sudo service mysql restart