Difference between basestring and str in python

In Python versions prior to 3.0 there are two kinds of strings "plain strings" and "unicode strings". Plain strings (str) cannot represent characters outside of the Latin alphabet (ignoring details of code pages for simplicity). Unicode strings (unicode) can represent characters from any alphabet including some fictional ones like Klingon.

So why have two kinds of strings, would it not be better to just have Unicode since that would cover all the cases? Well it is better to have only Unicode but Python was created before Unicode was the preferred method for representing strings. It takes time to transition the string type in a language with many users, in Python 3.0 it is finally the case that all strings are Unicode.

The inheritance hierarchy of Python strings pre-3.0 is:

 object
    |
    |
basestring
   / \
  /   \
str  unicode

'basestring' introduced in Python 2.3 can be thought of as a step in the direction of string unification as it can be used to check whether an object is an instance of str or unicode

>>> string1 = "I am a plain string"
>>> string2 = u"I am a unicode string"
>>> isinstance(string1, str)
True
>>> isinstance(string2, str)
False
>>> isinstance(string1, unicode)
False
>>> isinstance(string2, unicode)
True
>>> isinstance(string1, basestring)
True
>>> isinstance(string2, basestring)
True

Source: https://stackoverflow.com/questions/1979004/what-is-the-difference-between-isinstanceaaa-basestring-and-isinstanceaaa

Interesting python libraries that you can use for interacting with google spreadsheet

• gspread: see https://www.twilio.com/blog/2017/02/an-easy-way-to-read-and-write-to-a-google-spreadsheet-in-python.html and https://github.com/burnash/gspread

or

• google-api-python-client: https://www.youtube.com/watch?v=VLdrgE8iJZI&t=1s and https://developers.google.com/sheets/api/quickstart/python?utm_campaign=drive_launch_google_sheets_api_061416&utm_source=gdev&utm_medium=yt-desc

Using pip with different python version

Let us say that you have python2 and python3 installed.

Use pip for python2

pip2.6 install otherpackage
pip2.7 install mybarpackage

You can see which version of python pip is using by default with:

pip -V

Source: http://stackoverflow.com/questions/6504810/how-to-install-lxml-on-ubuntu?answertab=votes#tab-top

Introspection in python

Imagine that you are debugging and that you want to know the methods that you can call on an object, this pseudo code can be helpful. Here "some_object" is any python object:

[method for method in dir(some_object) if callable(getattr(some_object, method))]

Source: http://www.diveintopython.net/power_of_introspection/index.html

How to get first/last day of the previous month?

>>> from datetime import date
>>> from dateutil.relativedelta import relativedelta
>>> today = date.today()
>>> d = today - relativedelta(months=1)
>>> date(d.year, d.month, 1)
datetime.date(2008, 12, 1)
>>> date(today.year, today.month, 1) - relativedelta(days=1)
datetime.date(2008, 12, 31)
>>>

Abstraction in python

For example, when copying files:

import shutil
shutil.copy('file.txt', 'copy.txt')

It is much more abstract (and simpler) to use the shutil library than:

with open(src, 'rb') as fsrc:
    with open(dst, 'wb') as fdst:
        while True:
            buf = fsrc.read(buf_size)
            if not buf:
                break
            fdst.write(buf)