Index
Symbols
() characters
using, to break long statement into sensible pieces 60
* separator
about 127
used, for forcing keyword-only arguments 122, 124, 125, 127, 128
*, separator 127
** separator 127
/ separator
used, for defining position-only parameters 130, 132, 134
__slots__
small objects, optimizing with 297, 301, 302
A
Abstract Base Classes (ABCs) 146
abstract superclass 327
ACID properties
atomicity 729
consistency 729
durability 729
isolation 729
add method
used, for building sets
aggregation 310
alternate hypothesis 773
anonymous tuples
anscombe.json 734
append() method
used, for building lists 153
approaches, for designing functions with optional parameters
General to Particular design 104, 106
Particular to General design 102, 103, 104
argparse
using, to get command-line input 245, 247, 248, 250
arguments
processing, options
arrays 148
ASCII
creating
associative store 197
autocorrelation 764
computing 764, 766, 767, 768, 769, 770
long-term model 771
working 770
B
backslash
using, to break long statement into logical lines 58, 60
Beautiful Soup
reference link
block mapping 660
block sequence 660
block style
working 660
body elements
recognizing, with RST parser 76
bootstrapping
break statements
used, for avoiding potential problem
built-in collection
extending
built-in statistics library
using 734, 736, 737, 739, 740, 741
bytes
decoding
versus strings
C
Card objects
representation, transferring 564
Cascading Style Sheet (CSS)
Certificate Authority (CA)
characters
used, for building complicated strings 43
chunking 109
class-as-namespace
using, for configuration files 674, 676, 678, 679
class-as-namespace, for configuration files
configuration representation 682, 684
class definitions
type hints, using for 262, 264, 265, 267
used, for encapsulate class details 253, 255, 257, 258, 260
used, for processing class details 253, 255, 257, 258, 260
classes
designing, with processing 268, 269, 271, 273, 275, 276
classes, design alternatives for storing data
eager 269
lazy 269
classes, strategies for storing data
extend strategy 269
wrap strategy 269
class hierarchies
essential features 320
mixin features 320
class level variables
class with orderable objects
creating 346, 347, 348, 350, 351, 352
clear documentation strings
writing, with RST markup
CLI applications
combining 721, 722, 724, 726, 727, 729
wrapping 721, 722, 724, 726, 727, 729
cmd class
cmd module
using, to create command-line applications
code rot 697
coefficient of correlation
computing 752, 753, 754, 755, 756
collaborators 255
collection
summarizing 408, 410, 411, 412
collections
transformations, applying to 374, 376, 377, 378, 381
collections module
built-in collections 148
combining two applications into one
complex sequences of steps, controlling
conditional processing, building
output, checking
program, wrapping as Python class
with Command Design Pattern 704, 706, 707
combining two applications into one, areas of rework
about 697
structure 699
come-out roll 81
Command Design Pattern
used, for combining two applications into one 704, 706, 707
command-line applications
creating, with cmd module
command-line input
obtaining, with argparse 245, 247, 248, 250
Command-Line Interface (CLI) 710
comma-separated value (CSV) 339
comma-separated values (CSV) 454
complex algorithms
simplifying, with immutable data structures
complex data structure
deserializing
complex data structures
complex formats
reading, with regular expressions 469, 472, 478
complex formats, reading with regular expressions
log_parser() function, using 476, 478
parse function, defining 474, 476
complex if...elif chains
complex strings
building, with f strings 38, 39, 40
complex text
complicated objects list
items, deleting
complicated strings
building, with characters 43
composite
composite application
arguments, managing 710, 712, 714, 715, 716, 717, 719
configuration, managing 710, 712, 714, 715, 716, 717, 719
creating, issues 693
composite object validation 236
composites
creating, with combination of existing command 708, 710
comprehension 154
configuration files
class-as-namespace, using for 674, 676, 678, 679
finding 643, 644, 646, 648, 650
Python, using for 666, 667, 668, 670
YAML, using for 655, 657, 659, 660
context managers
creating
contexts
creating
managing, with statement used
copy of list
Counter object
average of values 745, 747, 748
Counter object, values
Coupon Collector�s Test 268
crib 285
CSV dialect 454
csv DictReader
refactoring, as dataclass reader
CSV files
working with, dataclasses used 463, 464, 465, 466
CSV module
delimited files, reading with 454, 456, 457, 459
currency 8
currency calculations
D
dataclasses
used, for working with CSV files 463, 464, 465, 466
using, for mutable objects 285, 287, 288, 290
dataclass reader
csv DictReader, refactoring as
data structure
arrays 148
graphs 150
hashes 150
trees 148
decimal
deep copies of objects
making
delimited files
reading, with CSV module 454, 456, 457, 459
del statement
used, for deleting items 167
used, for removing dictionaries 197, 199, 201, 202
dictConfig() function
using
dictionaries
building, as comprehension 192, 194
building, by setting items 192
building, ways 190
removing, with del statement 197, 199, 201, 202
removing, with pop() method 197, 199, 201, 202
updating, with statistical summaries 741, 742, 744, 745
dictionary-related type hints
difference() method
used, for removing items
difference_update()method
used, for removing items
directives
using 79
discrete integer-valued variable
docstrings
about 51
RST markup, writing 73, 75, 76
used, for testing 496, 498, 499
writing, for library modules 69
writing, for scripts 66, 68, 69
doctest examples
writing, for floating-point values 520
writing, with object IDs 519
writing, with unpredictable set ordering 518, 519
doctest issues
doctest module
working 504
doctest test cases
combining, with pytest test cases 549, 550, 551, 553
combining, with unittest test cases 537, 538, 539, 541, 542
doctest tool 55
document object model (DOM)
Document Type Definition (DTD)
Don�t Repeat Yourself (DRY) principle
E
edge cases
identifying 505
emergent behavior 255
end-to-end testing 491
escape sequences
except
clause
used, for avoiding potential problem
exception matching rules
leveraging
exception root cause
concealing
existential quantifier
explicit line joining 63
exploratory data analysis (EDA) 734
exponent 17
extend strategy 269
external resources
mocking
extra punctuation marks
removing 28
F
files
replacing, while preserving previous version 445, 447, 449, 450
filter() function
used, for rejecting items 171
using 405
First-In-First-Out (FIFO) 304
First Normal Form (1NF) 454
Flask framework
using, for RESTful APIs 572, 574, 575, 576, 578, 579
Flask�s documentation
reference link 583
float
floating-point
need for 17
floating-point approximations 11, 13
floor division
flow style 660
for statement
used, for applying parse_date() function to collections 378
fraction
about 8
frozen dataclasses
using, for immutable objects 292, 294, 296
f strings
used, for building complex strings 38, 39, 40
function parameters
mutable default values, avoiding for
functions
designing, with optional parameters 101, 106, 108
testing, that raise exceptions 507, 508, 509, 511, 512
functools.partial()
using
G
garbage collection 318
general domain validation 235
generalization-specialization relationship , 308
generator expression
list function, using 154
set function, using
used, for applying parse_date() function to collections 378
generator expressions
patterns 383
generator functions 371
applications, creating 373
writing, with yield statement 363, 365, 366, 368, 369, 371, 372
get_optionsO function 719
getpass() function
using, for user input 229, 231, 232, 233, 235
global objects
global singleton variables
creating 334
sharing, ways 337
graphs 150
H
half-open interval 29
has-a relationship 308
hashes 150
header row
excluding 389
heterogenous items 175
higher-order function
hints 138
homogenous items 175
HSL
HTML documents
reading
Hypertext as the Engine of State (HATEOS) 622
I
immutable data structures
used, for simplifying complex algorithms
immutable objects
frozen dataclasses, using for 292, 294, 296
typing.NamedTuple, using for 280, 282, 283
immutable string
implicit line joining 63
index-only tuples
inheritance 308, 309, 310, 314, 315, 316
inline markup
using 80
input() function
using, for user input 229, 231, 232, 233, 234, 235
instances 254
intermediate results
assigning, to separate variables 62
saving, with walrus operator 87, 89, 90
int() function, signatures
int(str) 101
int(str, base) 101
irrational numbers 8
is-a relationship 308
items
deleting, from complicated objects list
deleting, with del statement 167
deleting, with pop() method 169, 171
deleting, with remove() method 169
extracting, from tuples
rejecting, with filter() function 171
removing, with difference() method
removing, with pop() method
removing, with remove() method
replacing, with slice assignment 172
iterator 369
itertools module
about
additional functions
J
JavaScript Object Notation (JSON)
URL 482
JSON-based error messages
creating
JSON documents
structures 486
JSONLines
URL 488
JSON request
parsing, for client 639
parsing, for sever 636, 638, 639
parsing, OpenAPI specification 633, 635
parsing, with additional resources
parsing, with location header
JSON syntax
data structures 659
K
keyword-only arguments
forcing, with * separator 122, 124, 125, 127, 128
keyword parameters
disadvantage 121
used, for creating partial function
L
lambda object
creating
large integers
Last-In-First-Out (LIFO) 304
Law of the Excluded Middle 81
lazy attributes
properties, using for
lazy calculation
working
leaks
library modules
docstrings, writing for 69
line joining 63
Liskov Substitution Principle (LSP) 708
list comprehension
writing 154
list function
using, on generator expression 154
list-related type hints
lists
building, with append() method 153
dicing 160, 161, 162, 163, 164, 165
slicing 160, 161, 162, 163, 164, 165
lists, building ways
append method 151
comprehension 151
conversion function 151
generator expressions 152
literal 151
load_config_file() funtion
implementing, ways 646
load testing 491
logging.config module
using
logging module
used, for auditing output
used, for controlling output
logging package
severity levels
long lines of code
M
magic 55
mantissa 17
map
combining 416, 418, 420, 421, 422, 423, 425
map() function
used, for applying parse_date() function to collections 379
maps of lists
Median Absolute Deviation (MAD) 786
memorization technique
Method Resolution Order (MRO) 323, 683
modeline 56
modules, for writing summary docstrings
library modules 64
scripts 64
multiple contexts
managing, with multiple resources
multiple inheritance
concerns, separating via 319, 320, 321, 322, 323, 324
creating, ways 356
mutable default values
avoiding, for function parameters
mutable objects
dataclasses, using for 285, 287, 288, 290
Mypy documentation
reference link 100
mypy tool 93
N
NamedTuples
using, to simplify item access in tuples
Newline Delimited JSON
URL 488
numbers type
converting 13
O
Object-Relational Management (ORM) layer 693
objects 253
Observable design pattern 324
Observer design pattern 324
optional parameters
type hints, designing for 109, 111, 113
used, for designing functions 101, 106, 108
ordered collection
performance, improving with 354, 357, 358
order of dictionary keys
OS environment settings
using
outliers
overloaded function 101
P
parameters order
picking, based on partial functions
partial function
creating
partial functions
creating, with keyword parameters
creating, with positional parameters
order of parameters, picking based on
wrapping
pass_outliers() function
versus reject_outliers() function
pathlib
using, to work with filenames 430, 432, 433, 434
pathname manipulations
directory, creating in directory 436
file dates, comparing 438
files, creating in directory 436
files, removing 438
files with matching patterns, finding 439, 441
output filename, making by changing input filename�s suffix 434
sibling output files, making with distinct names 434, 436
Pearson�s r 752
percent encoding 589
piece of string
pop() method
used, for deleting items 169, 171
used, for removing dictionaries 197, 199, 201, 202
used, for removing items
positional parameters
used, for creating partial function
position-only parameters
defining, with / separator 130, 132, 134
potential problem
avoiding, with break statements
avoiding, with except
clause
prefixes
alternate form 40
fill and alignment 40
leading zero 40
sign 40
width and precision 40
print() function, features
pure paths 646
pytest module
used, for unit testing 543, 544, 546, 547, 548
pytest test cases
combining, with doctest test cases 549, 550, 551, 553
pytest tool 494
Python
advantages 722
features 729
URL 6
using, for configuration files 666, 667, 668, 670
Python Enhancement Proposal (PEP) 8 60
Python Enhancement Proposal (PEP) 484
reference link 55
Python module files
Python Package Index (PyPI)
reference link
Python script
Python�s duck typing
Python�s stack limits
recursive functions, designing around
pyyaml project
reference link 482
Q
query string
parsing, in request 583, 586, 587, 589
R
Rate-Time-Distance (RTD) 116
rational fraction calculations 22, 24
rational numbers 8
read-evaluate-print loop (REPL)
recursive functions
designing, around Python�s stack limits
recursive generator functions
writing, with yield from statement
reduce() function
application, designing 412
drawback 414
using, to customize maxima 414
using, to customize minima 414
reduction
reference counting 318
regression parameters
Regular Expression (RE) 32
regular expressions
complex formats, reading with 469, 472, 473, 478
used, for parsing strings 32, 34, 35, 36
reject_outliers() function
versus pass_outliers() function
remove() method
used, for deleting items 169
used, for removing items
Representational State Transfer (REST) 561
RESTful 561
RESTful APIs
Flask framework, using for 572, 574, 575, 576, 578, 579
RESTful APIs, with Flask
features, adding to sever 622
OpenAPI specification, providing for parsing URL path 624, 626, 627
OpenAPI specification, using for parsing URL path 629
URL path, parsing at client side 620, 622
URL path, parsing by slicing deck of cards 620
URL path, parsing for client 616, 617, 618, 619
URL path, parsing for sever 610, 612, 614, 615
URL path, parsing with CRUD operations 619
REST requests
making, with urllib 593, 595, 596, 598, 600
ReStructuredText (RST) markup 66
RGB
row_merge() function
creating, to restructure data 387, 388
RST markup
used, for writing clear documentation strings
writing, in docstrings 73, 75, 76
RST parser
body elements, recognizing 76
S
schema 454
script descriptions 64, 66, 69
script documentation 64, 66, 69
script-library switch
used, for writing testable scripts
scripts
designing, for composition 685, 687
docstrings, writing for 66, 68, 69
refactoring, to class
Secure Socket Layer (SSL) protocol 601
separate tests directory 535
set comprehension
writing
set function
using, on generator expression
set-related type hints
writing
sets
building, with add method
sets, building ways
add method
comprehension
conversion function
generator expressions
literal
shallow copies of objects
making
shallow copy 165
shebang 55
signature 101
singleton objects
slice assignment
used, for replacing items 172
slice operator 164
small integers
S.O.L.I.D. design principles
Dependency Inversion Principle 262
Interface Segregation Principle 261
Liskov Substitution Principle 260
Open/Closed Principle 260
Single Responsibility Principle 260
sophisticated collections
Sphinx Python Documentation Generator
reference link 80
spike solution
reference link 724
src 539
stacked generator expressions
using 383, 384, 386, 391, 392, 393, 395, 397
string literal concatenation
using 61
strings
encoding
parsing, with regular expressions 32, 34, 35
updating, with replacement 27, 28
versus bytes
subdomain validation 235
subset
selecting, to filter data 397, 399, 401, 403, 405, 406
summary of data, EDA
central tendency 734
extrema 734
variance 734
Swagger 603
T
tail recursion
takewhile() function
testable scripts
writing, with script-library switch
TestCase class 535
assertion methods 532
testing
docstrings, using for 496, 498, 499
testing, with docstrings
examples, writing for stateful objects 501, 503, 504
examples, writing for stateless functions 499, 501
tests 535
writing, with datetime object 555, 556, 557, 559
text role 80
there exists processing pattern
implementing
transformations
applying, to collections 374, 376, 377, 378, 381
reducing 416, 418, 420, 421, 422, 423, 425
trees 148
true division
about 24
performing 22
truncated division 24
tuples
creating
item access, simplifying with NamedTuples
items, extracting from
tuples of items
using
type hints
designing, for optional parameters 109, 111, 113
using, for class definitions 262, 264, 265, 267
writing, for complex types 134, 136, 138, 139
typing.NamedTuple
using, for immutable objects 280, 282, 283
U
Unicode characters
reference link
using
Unicode encodings
reference link
unit test algorithm
with randomness
unit testing
with pytest module 543, 544, 546, 547, 548
with unittest module 523, 525, 526, 527, 529, 531
unittest module
used, for unit testing 523, 525, 526, 527, 529, 531
unittest test cases
combining, with doctest test cases 537, 538, 539, 541, 542
URL encoding
urllib
REST requests, making with 593, 595, 596, 598, 600
urllib, using for making REST requests
OpenAPI resource, adding to sever 604, 605, 607
OpenAPI specification 603
useful row objects
user authentication 601
User Experience (UX) 712
user interaction
via cmd module 239
UTF-8 bytes
creating
UTF-8 encoding
reference link
V
analyzing, in one pass
variables, categories
categorical data
continuous real-valued data
count data
discrete data
ordinal data
W
walrus operator
about 47
used, for saving intermediate results 87, 89, 90
web services
HTTP basic authentication
HTTP bearer token authentication
web services authentication
example client, creating
implementing
server, creating
server, starting
User class, defining
view decorator, defining
web services authentication, parts
best practices, using for password hashing
decorator, using for secure view functions
SSL, using to provide secure channel
web services, authentication ways
certificates
HTTP headers
Web Services Gateway Interface (WSGI) 562, 579
web services, HTTP-based authentication
Flask view function decorator, using for
SSL, configuring for
user credentials, rules
web services, security implementation parts
authentication
authorization
with statement
used, for managing contexts
wrap strategy 269
X
XML
XML documents
reading
XML Path Language (XPath)
Y
YAML
features 662
features, examples 662, 663, 665
using, for configuration files 655, 657, 659, 660
YAML document
reading 482
yield from statement
used, for writing recursive generator functions
yield, from statement
used, for writing recursive generator functions
yield statement
used, for writing generator functions 363, 365, 366, 368, 369, 371, 372
Z
z-scores