Subversion Repositories Boeken.quickpython

10.2 First module

>>> pi
Traceback (innermost last):
  File "<stdin>", line 1, in ?
NameError: name 'pi' is not defined
>>> area(2)
Traceback (innermost last):
  File "<stdin>", line 1, in ?
NameError: name 'area' is not defined


>>> import mymath
>>> pi
Traceback (innermost last):
  File "<stdin>", line 1, in ?
NameError: name 'pi' is not defined
>>> mymath.pi
3.14159
>>> mymath.area(2)
12.56636
>>> mymath.__doc__
'mymath - our example math module'
>>> mymath.area.__doc__
'area(r): return the area of a circle with radius r.'


>>> from mymath import pi
>>> pi
3.14159
>>> area(2)
Traceback (innermost last):
  File "<stdin>", line 1, in ?
NameError: name 'area' is not defined


>>> import mymath, importlib
>>> importlib.reload(mymath)
<module 'mymath' from '/home/doc/quickpythonbook/code/mymath.py'>

10.5 Private names in modules

>>> from modtest import *
>>> f(3)
3
>>> _g(3)
Traceback (innermost last):
  File "<stdin>", line 1, in ?
NameError: name '_g' is not defined
>>> a
4
>>> _b
Traceback (innermost last):
  File "<stdin>", line 1, in ?
NameError: name '_b' is not defined

>>> import modtest
>>> modtest._b
2
>>> from modtest import _g
>>> _g(5)
5

10.7 10.7 Python scoping rules and namespaces

>>> locals()
{'__builtins__': <module 'builtins' (built-in)>, '__name__': '__main__', 
'__doc__': None, '__package__': None}
>>> globals()
{'__builtins__': <module 'builtins' (built-in)>, '__name__': '__main__', 
'__doc__': None, '__package__': None}>>> 


>>> z = 2
>>> import math
>>> from cmath import cos
>>> globals()
{'cos': <built-in function cos>, '__builtins__': <module 'builtins' 
(built-in)>, '__package__': None, '__name__': '__main__', 'z': 2,
'__doc__': None, 'math': <module 'math' from 
'/usr/local/lib/python3.0/libdynload/math.so'>}
>>> locals()
{'cos': <built-in function cos>, '__builtins__':
<module 'builtins' (built-in)>, '__package__': None, '__name__': 
'__main__', 'z': 2, '__doc__': None, 'math': <module 'math' from
'/usr/local/lib/python3.0/libdynload/math.so'>}
>>> math.ceil(3.4)
4


>>> del z, math, cos
>>> locals()
{'__builtins__': <module 'builtins' (built-in)>, '__package__': None, 
'__name__': '__main__', '__doc__': None}
>>> math.ceil(3.4)
Traceback (innermost last):
  File "<stdin>", line 1, in <module>
NameError: math is not defined
>>> import math
>>> math.ceil(3.4)
4


>>> def f(x):
...     print("global: ", globals())
...     print("Entry local: ", locals())
...     y = x
...     print("Exit local: ", locals())
...
>>> z = 2
>>> globals()
{'f': <function f at 0xb7cbfeac>, '__builtins__': <module 'builtins' 
(built-in)>, '__package__': None, '__name__': '__main__', 'z': 2, 
'__doc__': None}
>>> f(z)
global:  {'f': <function f at 0xb7cbfeac>, '__builtins__': <module 
'builtins' (built-in)>, '__package__': None, '__name__': '__main__', 
'z': 2, '__doc__': None}
Entry local:  {'x': 2}
Exit local:  {'y': 2, 'x': 2}
>>>

10.7  Python scoping rules and namespaces

>>> locals()
{'__builtins__': <module 'builtins' (built-in)>, '__name__': '__main__', 
'__doc__': None, '__package__': None}
>>> globals()
{'__builtins__': <module 'builtins' (built-in)>, '__name__': '__main__', 
>>> import scopetest
>>> z = 2
>>> scopetest.f(z)
global:  ['__name__', '__doc__', '__package__', '__loader__', '__spec__', '__file__', '__cached__', '__builtins__', 'v', 'f']
entry local: {'x': 2}
exit local: dict_keys(['x', 'w', 'y'])


>>> print(max.__doc__)
max(iterable[, key=func]) -> value
max(a, b, c, ...[, key=func]) -> value

With a single iterable argument, return its largest item.
With two or more arguments, return the largest argument.
>>>


>>> list("Peyto Lake")
['P', 'e', 'y', 't', 'o', ' ', 'L', 'a', 'k', 'e']
>>> list = [1, 3, 5, 7]
>>> list("Peyto Lake")
Traceback (innermost last):
  File "<stdin>", line 1, in ?
TypeError: 'list' object is not callable


>>> import mymath
>>> mymath = mymath.area
>>> mymath.pi
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'function' object has no attribute 'pi'


>>> del list
>>> list("Peyto Lake")
['P', 'e', 'y', 't', 'o', ' ', 'L', 'a', 'k', 'e']
>>> import mymath
>>> mymath.pi
3.14159


>>> x1 = 6
>>> xl = x1 - 2
>>> x1
6
>>> dir()
['__annotations__', '__builtins__', '__doc__', '__loader__', '__name__', '__package__', '__spec__', 'x1', 'xl']