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Introducing Python: Modern Computing in Simple Packages, Bill Lubanovic

SECOND EDITION:
Second edition, 2020, 597pp., ISBN 9781492051367

Errata:
p. 49 says 10**googol has 1000 zeroes. No, it has a googol (10**100) of zeroes.

2**(3**4) = 2**81
(2**3)**4 = 2**12


FIRST EDITION:

Introducing Python, Bill Lubanovic, 2015, 454pp. Dewey 005.133



This book is pretty good at getting you coding quickly. 


PYTHON

We get examples like this:

cheeses = []
for cheese in cheeses:
 print('This shop has some lovely', cheese)
 break
else: # no break means no cheese
 print('This is not much of a cheese shop, is it?')

(Chapter 4: Py Crust: Code Structures. p. 79 in 2015 edition.)


WARNING: INSTALLING AND RUNNING

The Anaconda installer doesn't support spaces in the file-path name. Instead of "Current User," install as root. The book doesn't warn you of that.
 

Then, since the executable and your files aren't in your user directory, when you want to run one of your scripts from a Windows powershell, you have to 

cd C:\ProgramData\Anaconda3

then you can enter

C:\ProgramData\Anaconda3> python test1.py

to run your 'test1' script, or whatever it may be.

The book doesn't tell you this.

Use Anaconda Navigator to open a Windows PowerShell: doing it from here activates the environment: necessary to get your scripts to run. The book doesn't say this.

 
has tutorial and quick-start guide
docs.anaconda.com 
 

 

MODULE SEARCH PATH?

We learn that Python looks for files to import based on a list "in the standard sys module." We don't learn where this module is. Chapter 5: Py Boxes: Modules, Packages, and Programs, p. 113 in the 2015 edition.

CAUTION

CODE SAMPLES from the book: the simple ones work. Those dependent on pulling datasets off the web do not work. 

 
has code examples from the book.


ARITHMETIC: CAUTION

10^2 evaluates to 8.
It's 10**2 that gives 100.

ASSIGNMENT STATEMENTS VS. FUNCTIONS

b = 5
c = 15
a = b + c
a
gives 20. So far so good. Now, though, after
b = 6
a
gives 20.
It's not enough to change the variable values: you have to redefine the function to get its output to change, if reassigning values to variables. You have to again say
a = b + c
now
a
gives 21.

YOU HAVE TO EXPLICITLY
import math

before you can do calculations like

math.sqrt(2)
1.4142135623730951

(although Python can do
2**.5
to give
1.4142135623730951
without the math library.)

math.log(10)
2.302585092994046

math.log(100, 10)
2.0

math.e
2.718281828459045

For the square root of a negative number, you have to explicitly import the complex math library:

import cmath

Then you can do

cmath.sqrt(-1)
1j

However, Python can do all this without importing the cmath library:

Pretty close:
(-1)**.5
(6.123233995736766e-17+1j)

(math.e)**(complex(0, ))
(6.123233995736766e-17+1j)

2.718281828459045**(complex(0, 3.141592653589793/2))
(6.123233995736766e-17+1j) 

x = complex(1, 1)
x**2
2j

2j**.5
(1.0000000000000002+1.0000000000000002j)








recommends
PYTHON FOR DATA ANALYSIS, WES MCKINNEY

Python Standard Library online documentation:
 

The Python Standard Library by Example, Doug Hellmann
 

Open-source Python software:

 

 

 

 

Introducing Python: Modern Computing in Simple Packages, Bill Lubanovic

SECOND EDITION:
Second edition, 2020, 597pp., ISBN 9781492051367

Errata:
p. 49 says 10**googol has 1000 zeroes. No, it has a googol (10**100) of zeroes.

2**(3**4) = 2**81
(2**3)**4 = 2**12


FIRST EDITION:

Introducing Python, Bill Lubanovic, 2015, 454pp. Dewey 005.133



This book is pretty good at getting you coding quickly. 


PYTHON

We get examples like this:

cheeses = []
for cheese in cheeses:
 print('This shop has some lovely', cheese)
 break
else: # no break means no cheese
 print('This is not much of a cheese shop, is it?')

(Chapter 4: Py Crust: Code Structures. p. 79 in 2015 edition.)


WARNING: INSTALLING AND RUNNING

The Anaconda installer doesn't support spaces in the file-path name. Instead of "Current User," install as root. The book doesn't warn you of that.
 

Then, since the executable and your files aren't in your user directory, when you want to run one of your scripts from a Windows powershell, you have to 

cd C:\ProgramData\Anaconda3

then you can enter

C:\ProgramData\Anaconda3> python test1.py

to run your 'test1' script, or whatever it may be.

The book doesn't tell you this.

Use Anaconda Navigator to open a Windows PowerShell: doing it from here activates the environment: necessary to get your scripts to run. The book doesn't say this.

 
has tutorial and quick-start guide
docs.anaconda.com 
 

 

MODULE SEARCH PATH?

We learn that Python looks for files to import based on a list "in the standard sys module." We don't learn where this module is. Chapter 5: Py Boxes: Modules, Packages, and Programs, p. 113 in the 2015 edition.

CAUTION

CODE SAMPLES from the book: the simple ones work. Those dependent on pulling datasets off the web do not work. 

 
has code examples from the book.


ARITHMETIC: CAUTION

10^2 evaluates to 8.
It's 10**2 that gives 100.

ASSIGNMENT STATEMENTS VS. FUNCTIONS

b = 5
c = 15
a = b + c
a
gives 20. So far so good. Now, though, after
b = 6
a
gives 20.
It's not enough to change the variable values: you have to redefine the function to get its output to change, if reassigning values to variables. You have to again say
a = b + c
now
a
gives 21.

YOU HAVE TO EXPLICITLY
import math

before you can do calculations like

math.sqrt(2)
1.4142135623730951

(although Python can do
2**.5
to give
1.4142135623730951
without the math library.)

math.log(10)
2.302585092994046

math.log(100, 10)
2.0

math.e
2.718281828459045

For the square root of a negative number, you have to explicitly import the complex math library:

import cmath

Then you can do

cmath.sqrt(-1)
1j

However, Python can do all this without importing the cmath library:

Pretty close:
(-1)**.5
(6.123233995736766e-17+1j)

(math.e)**(complex(0, ))
(6.123233995736766e-17+1j)

2.718281828459045**(complex(0, 3.141592653589793/2))
(6.123233995736766e-17+1j) 

x = complex(1, 1)
x**2
2j

2j**.5
(1.0000000000000002+1.0000000000000002j)








recommends
PYTHON FOR DATA ANALYSIS, WES MCKINNEY

Python Standard Library online documentation:
 

The Python Standard Library by Example, Doug Hellmann
 

Open-source Python software: