Comandos e funções

PROGRAMAÇÃO EM
JOGOS DIGITAIS
Frutuoso Silva
Linguagem de Programação
Python
--- www.python.org
1
Python Programming
Outras características interessantes do Python.
Tipagem dinâmica
! As variáveis e parâmetros não têm tipos
declarados, logo podem ser associados a objectos
de qualquer tipo em tempo de execução.
def dobro(x):
“Devolve duas vezes x”
return x + x
print dobro(2)
print dobro (“Dois”)
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Tipagem dinâmica
! As variáveis e parâmetros não têm tipos
declarados, logo podem ser associados a objectos
de qualquer tipo em tempo de execução.
def dobro(x):
“Devolve duas vezes x”
return x + x
print dobro(2)
4
print dobro (“Dois”)
DoisDois
Python commands/functions
! Compile and Exec
# Compile and exec commands
code = compile('a = 1+2', '<string>', 'exec')
exec code
print a
# executar uma expressão contida numa string
mycode = 'print "Execute the commands inside a
string"'
exec mycode
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Python commands/functions
! Compile and Eval
# Compile and exec commands
code = compile(‘1+2’, '<string>', ’eval')
print eval(code)
print eval(‘2*3’)
Python commands/functions
! Compile and Exec from a file
# Read the contents of file
with open('code1.py') as f:
data = f.read()
# Compile and exec from file
code_obj = compile(data, 'code1.py', 'exec')
exec(code_obj)
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Python commands/functions
! Compile and Exec from a file
# Read the contents of file
with open('code1.py') as f:
data = f.read()
code1.py
print "Print and execute this code!"
a=2*5
print "a= ", a
# Compile and exec from file
code_obj = compile(data, 'code1.py', 'exec')
exec(code_obj)
Print and execute this code!
a= 10
Python commands/functions
! Run the code in a file
# Other way to run the code of a file
execfile('code1.py')
Print and execute this code!
a= 10
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Python commands/functions
! Formatted writing - format(value, format_spec)
# Formatação de escrita – ex: tabela
headers = ["First name", "Last name"]
row1 = ["Jose", "Manuel"]
row2 = ["Maria", "João"]
row3 = ["Luis", "Silva"]
tablerows = [headers, row1, row2, row3]
fspec = "<15"
# Align left
fspec1 = ">15"
# Align right
fspec2 = "^15"
# Align center
for first,last in tablerows:
print(format(first, fspec) + “|” + format(last, fspec2))
Python commands/functions
! Formatted writing - format(value, format_spec)
# Formatação de escrita – ex: tabela
headers = ["First name", "Last name"]
row1 = ["Jose", "Manuel"]
First name
row2 = ["Maria", "João"]
Jose
row3 = ["Luis", "Silva"]
Mariarow3]
tablerows = [headers, row1, row2,
Luis
|
|
|
|
Last name
Manuel
Joaquina
Silva
fspec = "<15"
# Align left
fspec1 = ">15"
# Align right
fspec2 = "^15"
# Align center
for first,last in tablerows:
print(format(first, fspec) + “|” + format(last, fspec2))
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Python commands/functions
! Formatted writing - format(value, format_spec)
headers = ["First name", "Last name"]
row1 = ["Jose", "Manuel"]
===================
First name
| Last name
row3 = ["Luis", "Silva"]
Jose row3] | Manuel
tablerows = [headers, row1, row2,
Maria
| Joaquina
fspec = "<15"
# Align left
Luis
|
Silva
fspec2 = "^15"
# Align center
===================
row2 = ["Maria", "João"]
print “=”*31
for first,last in tablerows:
print(format(first, fspec) + “|” + format(last, fspec2))
print “=”*31
Python commands/functions
! Lambda functions
# Example 1
def f (x): return x**2
print f(8)
g = lambda x: x**2
print g(8)
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Python commands/functions
! Lambda functions
# Example 1
def f (x): return x**2
print f(8)
Vantagem: permite criar funções
em runtime.
g = lambda x: x**2
print g(8)
Python commands/functions
! Lambda functions
# Example 2
def make_repeater(n):
return lambda s: s * n
twice = make_repeater(2)
third = make_repeater(3)
fourth = make_repeater(4)
Vantagem: permite criar funções
em runtime.
print twice('word')
print third([2,3])
print fourth(5)
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Python commands/functions
! Lambda functions
# Example 3
lista = [2, 18, 9, 22, 17, 24, 8, 12, 27]
# Multiplos de 3
print filter(lambda x: x % 3 == 0, lista)
# Valores modificados
print map(lambda x: x * 2 + 10, lista)
# Soma valores
print reduce(lambda x, y: x + y, lista)
print sum(lista)
Python commands/functions
! Lambda functions
# Example 3
lista = [2, 18, 9, 22, 17, 24, 8, 12, 27]
print lista
[2, 18, 9, 22, 17, 24, 8, 12, 27]
# Multiplos de 3
print filter(lambda x: x % 3 == 0, lista)
[18, 9, 24, 12, 27]
# Valores modificados
46, 28, 54, 44, 58, 26, 34, 64]
print map(lambda x: x * 2 + 10, [14,
lista)
# Soma valores
print reduce(lambda x, y: x + y,139
lista)
139
print sum(lista)
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Python commands/functions
! Lambda functions
# Example 4
sentence = 'It is very cool and powerful'
words = sentence.split()
print words
lengths = map(lambda word: len(word), words)
print lengths
Python commands/functions
! Lambda functions
# Example 4
sentence = 'It is very cool and powerful'
words = sentence.split()
print words
lengths = map(lambda word: len(word), words)
print lengths
['It', 'is', 'very', 'cool', 'and', 'powerful']
[2, 2, 4, 4, 3, 8]
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Python commands/functions
! Lambda functions
# Example 5 – prime numbers
print "Prime numbers < 70"
nums = range(2, 70)
for i in range(2, 8):
nums = filter(lambda x: x == i or x % i, nums)
print nums
Prime numbers < 70
[2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67]
Python commands/functions
! Functional Programming
map()
! filter()
! reduce()
! ! and recursion
they are concepts used in functional programming.
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Python commands/functions
! Funções de introspecção
Python commands/functions
! Inspect
import os.path
import inspect
# módulo de introspecção "amigável”
print 'Object: ', inspect.getmodule(os.path)
print 'Class? ', inspect.isclass(str)
# Lista todas as funções que existem em "os.path”
print 'Members: ',
for name, struct in inspect.getmembers(os.path):
if inspect.isfunction(struct):
print name,
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Python commands/functions
! Inspect
import os.path
Object:
<module 'posixpath'
from de
'/Library/Frameworks/
import
inspect
# módulo
introspecção "amigável”
Python.framework/Versions/2.7/lib/python2.7/posixpath.pyc'>
print 'Object: ', inspect.getmodule(os.path)
Class? True
print 'Class? ', inspect.isclass(str)
Members: _joinrealpath abspath basename commonprefix dirname exists
# Lista
todasexpandvars
as funções
quegetctime
existem
em getsize
"os.path”
expanduser
getatime
getmtime
isabs isdir
isfile
islink
ismount
join
lexists
normcase
normpath
realpath
relpath
print 'Members: ',
samefile sameopenfile samestat split splitdrive splitext walk
for name, struct in inspect.getmembers(os.path):
if inspect.isfunction(struct):
print name,
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