# create a 3x4x2 3D-array using a dictionary with index tuples as keys
# initialize values to zero
arr3d = dict([((x,y,z), 0) for x in range(3) for y in range(4) 
    for z in range(2)])
 
# Python3 has dictionary comprehension to simplify this
#arr3d = {(x,y,z):0 for x in range(3) for y in range(4) for z in range(2)} 
 
# sorts the key index tuples
for ix in sorted(arr3d):
    print( "ix=%s val=%s" % (ix, arr3d[ix]) )
 
print('-'*20)
 
# change some values, basically assign to index
arr3d[2, 1, 0] = 5
arr3d[1, 0, 1] = 17
# or ...
ix = (0, 0, 0)
arr3d[ix] = 9
# or just ...
ix = 1, 1, 1
arr3d[ix] = 3
 
for ix in sorted(arr3d):
    print( "ix=%s val=%s" % (ix, arr3d[ix]) )
 
print('-'*20)
 
# get a specific value from a given index
print(arr3d[1, 1, 1])  # 3
# or ... 
ix = 0, 0, 0
print(arr3d[ix])  # 9
 
print('-'*20)
 
# get the lowest and highest key
low = (min(arr3d.keys()))    # --> (0, 0, 0) 
heigh = (max(arr3d.keys()))  # --> (2, 3, 1)
# show values
print( "ix=%s val=%s" % (low, arr3d[low]) )
print( "ix=%s val=%s" % (heigh, arr3d[heigh]) )
 
# get the heighest value in the array
print(max(arr3d.values()))  # 17
 
"""
my result -->
ix=(0, 0, 0) val=0
ix=(0, 0, 1) val=0
ix=(0, 1, 0) val=0
ix=(0, 1, 1) val=0
ix=(0, 2, 0) val=0
ix=(0, 2, 1) val=0
ix=(0, 3, 0) val=0
ix=(0, 3, 1) val=0
ix=(1, 0, 0) val=0
ix=(1, 0, 1) val=0
ix=(1, 1, 0) val=0
ix=(1, 1, 1) val=0
ix=(1, 2, 0) val=0
ix=(1, 2, 1) val=0
ix=(1, 3, 0) val=0
ix=(1, 3, 1) val=0
ix=(2, 0, 0) val=0
ix=(2, 0, 1) val=0
ix=(2, 1, 0) val=0
ix=(2, 1, 1) val=0
ix=(2, 2, 0) val=0
ix=(2, 2, 1) val=0
ix=(2, 3, 0) val=0
ix=(2, 3, 1) val=0
--------------------
ix=(0, 0, 0) val=9
ix=(0, 0, 1) val=0
ix=(0, 1, 0) val=0
ix=(0, 1, 1) val=0
ix=(0, 2, 0) val=0
ix=(0, 2, 1) val=0
ix=(0, 3, 0) val=0
ix=(0, 3, 1) val=0
ix=(1, 0, 0) val=0
ix=(1, 0, 1) val=17
ix=(1, 1, 0) val=0
ix=(1, 1, 1) val=3
ix=(1, 2, 0) val=0
ix=(1, 2, 1) val=0
ix=(1, 3, 0) val=0
ix=(1, 3, 1) val=0
ix=(2, 0, 0) val=0
ix=(2, 0, 1) val=0
ix=(2, 1, 0) val=5
ix=(2, 1, 1) val=0
ix=(2, 2, 0) val=0
ix=(2, 2, 1) val=0
ix=(2, 3, 0) val=0
ix=(2, 3, 1) val=0
--------------------
3
9
--------------------
ix=(0, 0, 0) val=9
ix=(2, 3, 1) val=0
17
 
"""

# using the local dictionary vars() to put
# variables into strings
 
name = "Harry"
name2 = "Verderchi"
 
for i in range(1, 5):
    # %d for integers and %s for strings
    print( "#%(i)d: %(name)s %(name2)s" % vars() )
 
"""
my result  -->
#1: Harry Verderchi
#2: Harry Verderchi
#3: Harry Verderchi
#4: Harry Verderchi
"""

# using string.Template() and the local dictionary vars()
# for formatted printing
 
import string
 
name = "Harry"
name2 = "Verderchi"
 
# create the template (note the $ before each variable name)
t = string.Template("#$i: $name $name2")
 
for i in range(1, 5):
    # use safe_substitute() for potential missing variables
    print( t.safe_substitute(vars()) )
 
"""
my output -->
#1: Harry Verderchi
#2: Harry Verderchi
#3: Harry Verderchi
#4: Harry Verderchi
"""

# extract the numeric value from a data string
# snee
 
def extract_number(data_str):
    """
    extract the numeric value from a string
    the string should contain only one number
    return the number as int, float or None
    """
    s = ""
    for c in data_str:
        if c in '1234567890.-':
            s += c
    if s:
        # convert number to int or float
        return eval(s)
    else:
        return None
 
 
data_raw = """
header
23 bushels
 43 years old
4323 Maiden Lane
-$23.44/kg
 +$12.32
footer
"""
 
# create a list of the string data
data_list = data_raw.split('\n')
print(data_list)  # test
 
print('-'*60)
 
# extract numeric values from the data in the list
for data_str in data_list:
    print(extract_number(data_str))
 
"""
my result -->
['', 'header', '23 bushels', ' 43 years old', '4323 Maiden Lane',
'-$23.44/kg', ' +$12.32', 'footer', '']
------------------------------------------------------------
None
None
23
43
4323
-23.44
12.32
None
None
"""

# Python30 has a module fraction that allows you to
# calculate with fractions, the result is a fraction
# is more precise than using floating point numbers
# ene
 
from fractions import Fraction
 
# Fraction(numerator, denominator)
# for instance fraction 2/3 would be Fraction(2, 3)
a = Fraction(2, 3)
b = Fraction(2, 5)
c = Fraction(3, 7)
 
print( "%s + %s = %s" % (a, b, a + b) )
print( "%s + %s + %s = %s" % (a, b, c, a + b + c) )
print( "(%s + %s)/(%s) = %s" % (a, b, c, (a + b)/c) )
 
"""
my display -->
2/3 + 2/5 = 16/15
2/3 + 2/5 + 3/7 = 157/105
(2/3 + 2/5)/(3/7) = 112/45
"""

# Python3.1 allows formatting of thousands
# and defaults format indexing in print()
# ene
 
n = 123456789
print(format(n, ',d'))
 
"""
my display -->
123,456,789
"""
 
m = 1234567.8912
print(format(m, ',.2f'))
 
"""
my display -->
1,234,567.89
"""
 
amount = format(1234567, ',d')
price = format(1234.56, ',.2f')
# note that {} defaults to the proper arg index
print('{} bottles at ${} each'.format(amount, price))
 
"""
my display -->
1,234,567 bottles at $1,234.56 each
"""

# print a 16 column table of ASCII characters from 0 to 127
 
# dictionary of non-printable asccii characters
controls_dic = {
0: 'NUL', 1: 'SOH', 2: 'STX', 3: 'ETX', 4: 'EOT', 5: 'ENQ', 6: 'ACK',
7: 'BEL', 8: 'BS', 9: 'HT', 10: 'LF', 11: 'VT', 12: 'FF', 13: 'CR',
14: 'SO', 15: 'SI', 16: 'DLE', 17: 'DC1', 18: 'DC2', 19: 'DC3',
20: 'DC4', 21: 'NAK', 22: 'SYN', 23: 'ETB', 24: 'CAN', 25: 'EM',
26: 'SUB', 27: 'ESC', 28: 'FS', 29: 'GS', 30: 'RS', 31: 'US'
}
 
n = 1
for k in range(0, 128):
    if k < 32:
        s = controls_dic[k]
    else:
        s = chr(k)
    if n % 16 > 0:
        print "%4s" % s,
    else:
        print "%4s" % s
    n += 1

def fuzzyequals(a, b, delta=0.0000001):
    """
    returns true if a is between b-delta and b+delta
    used for comparison of floating point numbers a and b
    """
    return abs(a-b) < delta
 
a = 0.61
c = 0.49
b = 1.1 - c  # b should be 0.61
 
# fuzzy comparison
if fuzzyequals(a, b):
    print("fuzzy_true")
else:
    print("fuzzy_false")
 
# direct comparison
if a == b:
    print("direct_true")
else:
    print("direct_false")
 
# shows true floating point number representation
print("should be [0.61, 0.61, 0.49]")
print([a, b, c])
 
"""
my output -->
fuzzy_true
direct_false
should be [0.61, 0.61, 0.49]
[0.60999999999999999, 0.6100000000000001, 0.48999999999999999]
"""

def frange(start=0, stop=0, step=1.0):
    """similar to xrange, but handles floating point numbers"""
    if step <= 0:
        while start > stop:
            yield start
            start += step
    else:
        while start < stop:
            yield start
            start += step
 
# testing ...
for x in frange(1.5, 4.7):
    print(x)
 
print("-"*20)
 
for x in frange(17, 4, -2.9):
    print(x)
 
print("-"*20)
 
for x in frange(stop=2.5, step=0.4):
    print(x)
 
print("-"*20)
 
print(list(frange(1.5, 5.2)))
 
 
"""
my output -->
1.5
2.5
3.5
4.5
--------------------
17
14.1
11.2
8.3
5.4
--------------------
0
0.4
0.8
1.2
1.6
2.0
2.4
--------------------
[1.5, 2.5, 3.5, 4.5]
"""

# add the proper suffix to integer numbers
# the suffix list index coincides with the number
# apply modulus 100 for numbers that exceed the list index
# snee
 
# list_0to9 also holds true for list_20to29 etc.
list_0to9 = ['th', 'st', 'nd', 'rd'] + ['th']*6
# 11th to 13th are exceptions
list_10to19 = ['th']*10
 
# suffix list for numbers 0 to 99
suffix_list = list_0to9 + list_10to19 + (list_0to9)*8
 
#print suffix_list
 
# test it
for x in range(1000):
    # use modulus 100 to recycle through the list
    # in case numbers exceed the list index
    print( "%d%s" % (x, suffix_list[x%100]) )
 
"""
part of my output -->
0th
1st
2nd
3rd
4th
5th
6th
7th
8th
9th
10th
11th
12th
13th
14th
15th
16th
17th
18th
19th
20th
21st
22nd
23rd
24th
25th
...
...
990th
991st
992nd
993rd
994th
995th
996th
997th
998th
999th
"""

# test the sqlite3 module, write and read a database file
# note that Python 2.5 and higher versions have sqlite3 builtin
# sqlite3.connect(database, timeout=5.0, isolation_level=None,
#   detect_types=0, factory=100)
# timeout=5.0 --> allows multiple access for 5 seconds (for servers)
# isolation_level=None -->  autocommit mode
# detect_types=0 --> native types TEXT, INTEGER, FLOAT, BLOB and NULL
# factory=100 --> statement cache to avoid SQL parsing overhead
# tested with Python 2.5 and Python 3.0
# snee
 
import sqlite3
 
# create/connect to a permanent file database
#con = sqlite3.connect("my_db.db3")
# for temporary testing you can use memory only
con = sqlite3.connect(":memory:")
 
# establish the cursor, needed to execute the connected db
cur = con.cursor()
 
# create/execute a table:
cur.execute('CREATE TABLE IF NOT EXISTS clients \
    (id INT PRIMARY KEY, \
    firstname CHAR(60), \
    lastname CHAR(60))')
 
# insert several lines at once using a
# list of (id, firstname, lastname) tuples
# use try/except or the existing db will complain about
# the non-unique id since it is already in the db
try:
    clients = [
    (106, "Hugo", "Winterhalter"),
    (107, "Ella", "Fitzgerald"),
    (108, "Louis", "Armstrong"),
    (109, "Miles", "Davis")
    ]
    cur.executemany("INSERT INTO clients (id, firstname, lastname) \
        VALUES (?, ?, ?)", clients )
except:
    pass
 
# add another client
# again, use try/except or the existing db will complain about
# the non-unique id if it is already in the db
try:
    new_client = (110, "Benny", "Goodman")
    cur.execute("INSERT INTO clients (id, firstname, lastname) \
        VALUES (?, ?, ?)", new_client)
except:
    pass
 
# important if you make changes to the database
# commits current data to the db file (data is persistant now)
con.commit()
 
# now test it
# get data row by row
print("Show data row by row:")
# also tell it to sort/order data by lastname
cur.execute('SELECT id, firstname, lastname FROM clients \
    ORDER BY lastname')
for row in cur:
    print(row)
 
print('-'*40)
 
# select just one data item from each row ...
cur.execute('SELECT firstname FROM clients')
print(cur.fetchall())
 
print('-'*40)
 
# or ...
cur.execute('SELECT firstname FROM clients')
for row in cur:
    print(row[0])
 
print('-'*40)
 
# select a specific data row ...
cur.execute('SELECT * FROM clients WHERE lastname="Davis"')
print(cur.fetchall())
 
# finally ...
con.close()
 
"""
my output -->
Show data row by row:
(108, u'Louis', u'Armstrong')
(109, u'Miles', u'Davis')
(107, u'Ella', u'Fitzgerald')
(110, u'Benny', u'Goodman')
(106, u'Hugo', u'Winterhalter')
----------------------------------------
[(u'Ella',), (u'Louis',), (u'Miles',), (u'Benny',), (u'Hugo',)]
----------------------------------------
Ella
Louis
Miles
Benny
Hugo
----------------------------------------
[(109, u'Miles', u'Davis')]
"""