add __init__ generation

README.md

@@ -31,16 +31,41 @@ class Person:
         self.age = age
         self.backpack = backpack
         self.salary = salary
+```
+Also, it is  possible to autogenerate `__init__`:
+```python
+from pankoff.magic import autoinit
 
+@autoinit
+class Person:
+    name = String()
+    age = Number(min_value=18, max_value=100)
+    backpack = combine(Type, Sized, types=(list,), min_size=5)
+    salary = Salary(amount=100, currency="USD")
 
+# pass `verbose=True` to `autocommit` in order to see generated source:
+@autoinit(verbose=True)
+class Person:
+    ...
+# prints:
+"""
+def __init__(self, name, age, backpack, salary):
+	self.name = name
+	self.age = age
+	self.backpack = backpack
+	self.salary = salary
+"""
+```
+## Now, let's create an instance:
+```python
 person = Person(
     name="John",
     age=18,
     backpack=[1, 2, 3, 4, 5],
     salary="100 USD"
 )
 ```
-## Now, lets try invalid data:
+### Lets try invalid data:
 ```python
 
 person = Person(

pankoff/magic.py

@@ -0,0 +1,27 @@
+from pankoff.base import BaseValidator
+
+init_template = "def __init__({arguments}):\n\t{assignments}"
+
+
+def autoinit(klass=None, verbose=False):
+    def inner(cls):
+        attrs = ["self"]
+        assignments = []
+        namespace = {}
+        for attr in vars(cls).values():
+            if isinstance(attr, BaseValidator):
+                attrs.append(attr.attr_name)
+                assignments.append(f"self.{attr.attr_name} = {attr.attr_name}")
+        init = init_template.format(
+            arguments=", ".join(attrs),
+            assignments="\n\t".join(assignments or ["pass"])
+        )
+        if verbose:
+            print(init)
+        exec(init, namespace)
+        cls.__init__ = namespace["__init__"]
+        return cls
+
+    if klass is not None:
+        return inner(klass)
+    return inner

setup.py

@@ -1,6 +1,6 @@
 from distutils.core import setup
 
-version = "2.0"
+version = "3.0"
 setup(
     name='pankoff',  # How you named your package folder (MyLib)
     packages=['pankoff'],  # Chose the same as "name"