import types
class Blender:
"""blends values into the given pattern.replace
if neither values nor pattern are defined a default
pattern is being created that prints the values of
the instance in the format [name1: value1, name2 = value2, ...]
"""
def __init__(self, pattern = None, values = None,
startToken = "${", endToken = "}"):
"""initializes the instance with defaultvalues.
that is the start and the end token
"""
self.BlendPattern = pattern
self.BlendValues = values
self.StartToken = startToken
self.EndToken = endToken
def blend(self, values = None, pattern = None):
"""blends the values into the given pattern"""
values = self.getValues(values)
pattern = self.getPattern(pattern, values)
for name in values.keys():
id = self.getTokenName(name)
value = values[name]
pattern = pattern.replace(id, str(value))
return pattern
def getValues(self, values):
""" returns the dictionary of values.
if no values are supplied this
instance is returned as a dictionary."""
if values == None:
if self.BlendValues == None:
values = self.__dict__
else:
values = self.BlendValues
if type(values) != types.DictionaryType:
values = values.__dict__
return values
def getBasePattern(self, values):
"""returns a pattern in the format
[name1: value1, name2: value2, ...]
excluding the instance-attributes of this class
"""
names = values.keys()
names.sort()
result = "["
for name in names:
if name not in ["BlendPattern",
"BlendValues",
"StartToken",
"EndToken"]:
result += name + ": " + self.getTokenName(name) + ", "
return result[0:-2] + "]"
def getPattern(self, pattern, values):
"""returns a pattern for this instance. if no pattern is defined
returns a default-pattern.
"""
if pattern == None:
if self.BlendPattern == None:
pattern = self.getBasePattern(values)
else:
pattern = self.BlendPattern
return pattern
def getTokenName(self, name):
"""returns the tokenname bound by the start and end token.
"""
return self.StartToken + name + self.EndToken
def __str__(self):
return self.blend()
class Person(Blender):
def __init__(self, name, lastName):
Blender.__init__(self)
self.Name = name
self.LastName = lastName
class User(Person):
def __init__(self, id, name, lastName):
Person.__init__(self, name, lastName)
self.ID = id
class Login(Blender):
def __init__(self):
Blender.__init__(self)
self.BlendPattern = """
Hello ${Name} ${LastName}!
Your Userid is: ${ID}.
You are logged into domain ${Domain}.
"""
class UserQuery(Blender):
def __init__(self, values):
pattern = """
SELECT *
FROM User
WHERE
id = ${ID} AND
domain like '${Domain}'
"""
Blender.__init__(self, pattern, values)
if __name__ == "__main__":
p = Person("Robert", "Kuzelj")
print p
u = User("007", "Robert", "Kuzelj")
print u
login = Login()
login.Name = "Robert"
login.LastName = "Kuzelj"
login.ID = 7
login.Domain = "python.org"
print login
sql = "SELECT * from User WHERE id=:{ID} AND domain like ':{Domain}'"
print Blender(sql, {"Domain": "python.org", "ID": "007"}, ":{", "}")
print UserQuery(login)
