Summer of code 2017: Python local help files

As explained in my Summer of code 2017: Python post I decided to pick up Python

I noticed that Python ships with a help file in chm format ( Compiled HTML Help)



Microsoft Compiled HTML Help is a Microsoft proprietary online help format, consisting of a collection of HTML pages, an index and other navigation tools. The files are compressed and deployed in a binary format with the extension .CHM, for Compiled HTML. The format is often used for software documentation.

I haven't used a chm file since SQL Server 2000 within Query Analyzer. I prefer these files over online files for multiple reason

You don't have to be online to access the help file, you can be coding in a cave without connectivity and you can still pull up help

You can bookmark pages you want to get back to over and over again, these will be in the favorites tab

There is an index tab, this is like the back of a book, it is in alphabetical order and you can quickly find stuff

I typed in string, hit enter and saw the following

Then I clicked on method and was presented with the page you see

Do you use the local help file or do you use the online documentation?

Summer of code 2017: Python, Day 2

As explained in my Summer of code 2017: Python post I decided to pick up Python

Today is officially day 2

I decided to do a lunch and learn today and continue with the PluralSight course: Python Fundamentals

The course continued with Strings. Strings are very similar as strings in other languages

Here are some of the notes for myself of what I learned today


You can use single or double quotes with strings

Universal Newlines, you can use "\n" and it will be a newline on all platforms, this is also part of PEP 278

Multi-line strings are created by using triple quotes

For example

>>> x = """fdfdfdf
dfd
fdf
df
dfdf"""
>>> x
'fdfdfdf\ndfd\nfdf\ndf\ndfdf'
>>> 

As you can see, when the console prints the string, you will see the \n escape characters

Here are some of these escape characters

Escape Sequence	Meaning	Notes
\newline	Backslash and newline ignored
\\	Backslash (\)
\'	Single quote (')
\"	Double quote (")
\a	ASCII Bell (BEL)
\b	ASCII Backspace (BS)
\f	ASCII Formfeed (FF)
\n	ASCII Linefeed (LF)
\r	ASCII Carriage Return (CR)
\t	ASCII Horizontal Tab (TAB)
\v	ASCII Vertical Tab (VT)
\ooo	Character with octal value ooo
\xhh	Character with hex value hh

Escape sequences only recognized in string literals are:

Escape Sequence	Meaning	Notes
\N{name}	Character named name in the Unicode database
\uxxxx	Character with 16-bit hex value xxxx
\Uxxxxxxxx	Character with 32-bit hex value xxxxxxxx

More about that here: https://docs.python.org/3/reference/lexical_analysis.html#strings

Formatted String Literals

A formatted string literal or f-string is a string literal that is prefixed with 'f' or 'F'. These strings may contain replacement fields, which are expressions delimited by curly braces {}. While other string literals always have a constant value, formatted strings are really expressions evaluated at run time.

Here is an example

>>> name = "Denis"
>>> f"He said his name is {name!r}."
"He said his name is 'Denis'."
>>> 

Strings are unicode and encoded in UTF-8

After strings, the course continued with bytes, lists, dictionaries and loops

Modularity

This was the next part of this course
Named functions are defned with the def keyword

def function_name(arg1, argn):


For example

>>> def sumvalues(x,y):
    return x + y

>>> sumvalues(4,5)
9
>>> 

If you use a return without a value, the function will return None, but remember that None is not printed from the REPL

If you were to save this function into a file and then import it, it would execute immediately

Python has special attributes that start and end with double underscores, we will look at __main__ and  __name__

'__main__' is the name of the scope in which top-level code executes. A module’s __name__ is set equal to '__main__' when read from standard input, a script, or from an interactive prompt.

A module can discover whether or not it is running in the main scope by checking its own __name__, which allows a common idiom for conditionally executing code in a module when it is run as a script or with python -m but not when it is imported:

Here is an example of that

>>> 
def sumvalues(x,y):
    return x + y

    if __name__ == "__main__":
        sumvalues(x,y)

>>> sumvalues(1,2)
3
>>> 

More here: https://docs.python.org/3/library/__main__.html


I also learned about setting up a main() function

Command line arguments are accessible via sys.argv

This module also covered documenting your code by using docstrings. 

Docstrings are standalone literal strings which are the fist statement
of a function or module

If you have this function

>>> def fib2(n):  # return Fibonacci series up to n
    """Return a list containing the Fibonacci series up to n."""
    result = []
    a, b = 0, 1
    while a < n:
        result.append(a)    # see below
        a, b = b, a+b
    return result

Now if you do a help(fib2) command, you will see the following

>>> help(fib2)
Help on function fib2 in module __main__:

fib2(n)
    Return a list containing the Fibonacci series up to n.

>>> 

I feel I need to spend more time with __main__ and __name__.  

I will do that the next couple of days

Summer of code 2017: Python, Day 1

As explained in my Summer of code 2017: Python post I decided to pick up Python

Today is officially day 1... but I really started yesterday

I decided to start with the PluralSight course: Python Fundamentals

This course is presented by  Austin Bingham and Robert Smallshire

This is the description for that course

Python Fundamentals gets you started with Python, a dynamic language popular for web development, big data, science, and scripting. What’s so great about Python? Python is powerful. The Python language is expressive and productive, it comes with a great standard library, and it’s the center of a huge universe of wonderful third-party libraries. With Python you can build everything from simple scripts to complex applications, you can do it quickly, and you can do it with fewer lines of code than you might think possible. But for many people those reasons take back-seat to something more important: Python is fun! Python’s readable style, quick edit-and-run development cycle, and “batteries included” philosophy mean that you can sit down and enjoy writing code rather than fighting compilers and thorny syntax. As your experiments become prototypes and your prototypes become products, Python makes the experience of writing software not just easier but truly enjoyable. In the words of Randall Munroe, "Come join us! Programming is fun again!"

Long integers

Python supports really long integers, most languages I worked with support up to 64 bit integers

In Python you can store 2 to the power of 900 in an integer without a problem

That looks like this in scientific notation

8.452712498170644e+270

Or if you were to print this out as an integer

8452712498170643941637436558664265704301557216577944354047371344426782440907597751590676094202515006314790319892114058862117560952042968596008623655407033230534186943984081346699704282822823056848387726531379014466368452684024987821414350380272583623832617294363807973376

That is 271 digits

Here is what it looks like in the console

>>> x = math.pow(2,900)
>>> print ( int(x))
84527124981706439416374365586642657043015572
16577944354047371344426782440907597751590676
09420251500631479031989211405886211756095204
29685960086236554070332305341869439840813466
99704282822823056848387726531379014466368452
68402498782141435038027258362383261729436380
7973376
>>> print ( len(str(x)))
22
>>> print ( len(str(int(x))))
271
>>> 

Python Enhancement Proposal (PEP)

Python's development is conducted largely through the Python Enhancement Proposal (PEP) process. The PEP process is the primary mechanism for proposing major new features, for collecting community input on an issue, and for documenting the design decisions that have gone into Python.

And index with all the PEPs can be found here: https://www.python.org/dev/peps/

PEP number 8 Style Guide for Python Code is an important one, all Python developers should keep that in mind. In this PEP you will see that you should use spaces not tabs for indentation, You should use 4 spaces per indentation level.


Zen of Python

This is another PEP, the Zen of Python is PEP number 20

The Zen of Python is a collection of 20 software principles that influences the design of Python Programming Language, 19 of these are written down, you can see them by entering the statement import this in the Python interpreter


>>> import this
The Zen of Python, by Tim Peters

Beautiful is better than ugly.
Explicit is better than implicit.
Simple is better than complex.
Complex is better than complicated.
Flat is better than nested.
Sparse is better than dense.
Readability counts.
Special cases aren't special enough to break the rules.
Although practicality beats purity.
Errors should never pass silently.
Unless explicitly silenced.
In the face of ambiguity, refuse the temptation to guess.
There should be one-- and preferably only one --obvious way to do it.
Although that way may not be obvious at first unless you're Dutch.
Now is better than never.
Although never is often better than *right* now.
If the implementation is hard to explain, it's a bad idea.
If the implementation is easy to explain, it may be a good idea.
Namespaces are one honking great idea -- let's do more of those!
>>>

That output is the Zen of Python

None

The equivalent of NULL in languages like c#, Java or SQL Server in Python is None

If you assign the None value to a variable and then tried to print it, you won't get anything back

You can however check if a variable has no value by checking for None

>>> y = None

>>> y

>>> 

if y == None:

    print("is none")

else:

    print("is none")

    

is none

I also messed around and struggled to install PyGame, at the end it was pretty simple, you can read that here:  Installing Pygame on windows

Installing Pygame on windows

As explained in my Summer of code 2017: Python post I decided to pick up Python. As explained in that post my son wants to do some game development. with Python you can use Pygame to do game development.

My first attempt to install Pygame didn't end well, the instructions I found were to were to download the pygame wheel file, rename the .whl file to .zip. After that extracting the files into a folder. Then you had to move the header files into the \Python36\include folder. Another thing I had to do was moving the pygame folder and the pygame-1.9.3.dist-info folder into the \Python36\Lib\site-packages folder

After that was done, I got some strange errors, something about init() missing (AttributeError: module 'pygame' has no attribute 'init')


Another option was to use pip

I tried that

C:\Users\dgobo>pip install pygame
Collecting pygame
  Downloading pygame-1.9.3-cp36-cp36m-win_amd64.whl (4.2MB)
    100% |████████████████████████████████| 4.2MB 234kB/s
Installing collected packages: pygame
Successfully installed pygame-1.9.3

I still had an error after this was done

I noticed that pip installed Pygame into the following folder

\anaconda3\lib\site-packages


Hmmm... what is anaconda and why did pip install Pygame there?

I then navigated to the Python directory, instead of pip install pygame I did python -m pip install pygame

C:\Python36>python -m pip install pygame
Collecting pygame
  Using cached pygame-1.9.3-cp36-cp36m-win_amd64.whl
Installing collected packages: pygame
Successfully installed pygame-1.9.3


That did it, after that ran, I had no errors anymore

So all you have to do is..run pip from python, not by itself

Hopefully this will help someone if they run into this issue

Summer of code 2017: SyntaxError: Missing parentheses in call to 'print'

As explained in my Summer of code 2017: Python post I decided to pick up Python

I looked at some examples and when I tried to run them I was getting an error

It was a pretty simple print statement

print 'Hello world'

Running that produced an error

Python 3.6.0 (v3.6.0:41df79263a11, Dec 23 2016, 08:06:12) [MSC v.1900 64 bit (AMD64)] on win32
Type "copyright", "credits" or "license()" for more information.
>>> print 'Hello world'
SyntaxError: Missing parentheses in call to 'print'

It tuns out, the example I was looking at was for Python 2. In Python 2, print was a distinct statement, in Python 3 print is actually a function call. Function calls require parentheses

If I changed the print statement to the following by adding parentheses.

>>> print ('Hello world')
Hello world

Running that worked fine.

Maybe this will help some other poor soul in the future......

Summer of code 2017: Python

I decided to learn/use a language that I don't use for work. I picked Python, I messed around with Python a little 10 years ago or so but decided to give it another shot for 2 reasons.

1) A lot of data scientists are using python in addition to R. Python and R are built into SQL Server 2017, so I might have to support either of these language in the future.

2) My youngest son wants to get into game programming, he will turn 11 next month, he has been messing around with scratch for the past year but wants to do some actual coding this time. I thought Python with pygame would be a good start


So what is the plan?

The idea is to start on Monday June 19th and finish this by August 16, this is 8 weeks, that should be enough to get to a certain skill level

My son has the python book for absolute beginners, he can start on that. Both of us can also watch and download the exercises from Pluralsight

I have already bookmarked the following courses

I installed Visual Studio 2017 yesterday and made sure to add python as part of that install. Here is what it looks like....

I have not used Visual Studio for a long time so I have to also get familiar with this latest version

The idea is also to post several times a week with updates on how it is going, what both my son and myself learned and how it is going in general

Kaizen Day 44, May 25 2017

This post is part of my daily kaizen routine, this is day 44 of that routine



Whenever I plan to go to the city I set my alarm to go off at 4 AM. I will always wake up by myself around 3:57 AM, the alarm will almost never go off while I am still sleeping. Today I woke up at 3:30 AM. I decided to get up...what is the point trying to get another 15 minutes of sleep in

I made myself a cold brew coffee the night before and I drank this between 4 and 4:30 AM

I left the house at 4:30 AM, walked to the train station, this took 40 minutes. I caught the 5:20 train, I read about 30 pages of the book Born to Run by Bruce Springsteen . The train arrived at  Newark at 5:55 or so, got on the PATH train and arrived at the World Trade Center station around 6:20

I then walked to the New York Sports Club gym on Broad street and did 30 minutes of cardio which burned a total of 361 calories





For breakfast I had some yogurt and fruit

I had a apple as a snack

For lunch I had a cheese sandwich and a burrito


For dinner we had egg noodles with homemade bolognese sauce, we had sauteed cauliflower on the side

I had a handful of chocolate chips for dessert




Activity for the day
Total steps:  23,628
Total floors: 34
Total distance: 10,9 miles