data structures completed

submissions/eoneoff/data-structures-http/data_structures/__init__.py

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+from .stack import Stack
+from .linked_list import LinkedList

submissions/eoneoff/data-structures-http/data_structures/linked_list.py

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+from .node import Node
+
+class LinkedList:
+    def __init__(self):
+        self._root = None
+        self._length = 0
+
+    def __iter__(self):
+        current = self._root
+        while current:
+            yield current
+            current = current.next
+
+    def insert(self, value, successor = None):
+        if(successor and self._root.value != successor):
+            for node in self:
+                if node.next and node.next.value == successor:
+                    node.next = Node(value, node.next)
+                    self._length+=1
+                    return
+            error_message = f'Value {successor} is not in the list'
+            raise ValueError(error_message)
+        else:
+            self._root = Node(value, self._root)
+            self._length+=1
+
+    def remove(self, value):
+        if self._root.value == value:
+            self._root = self._root.next
+            self._length-=1
+            return
+        for node in self:
+            if node.next and node.next.value == value:
+                node.next = node.next.next
+                self._length-=1
+                return
+        error_message = f'Value {value} is not in the list'
+        raise ValueError(error_message)
+
+    def show_list(self):
+        return [node.value for node in self]
+
+    def __len__(self):
+        return self._length

submissions/eoneoff/data-structures-http/data_structures/node.py

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+class Node:
+    def __init__(self, value = None, next = None):
+        self._value = value
+        self._next = next
+
+    @property
+    def value(self):
+        return self._value
+
+    @value.setter
+    def value(self, value):
+        self._value = value
+
+    @property
+    def next(self):
+        return self._next
+
+    @next.setter
+    def next(self, value):
+        self._next = value

submissions/eoneoff/data-structures-http/data_structures/stack.py

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+from .node import Node
+
+class Stack:
+    def __init__ (self):
+        self._root = None
+        self._length = 0
+
+    def push(self, value):
+        self._root = Node(value, self._root)
+        self._length+=1
+
+    def pop(self):
+        if self._length:
+            out = self._root.value
+            self._root = (self._root or None) and self._root.next
+            self._length-=1
+            return out
+        else: return None
+
+    def __len__(self):
+        return self._length

submissions/eoneoff/data-structures-http/main.py

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+"""Data structues with html assess
+
+    The assess to data structues is provided through html requests
+
+    stack
+        <socket>/stack
+
+        POST request with json object of format {"data":<value to push to stack>} pushes vaule to stack
+
+        DELETE request pops a value from a stack and returns in in json object of format
+        {"data": <value popped from stack}
+
+    linked list
+        <socket>/list
+
+        GET request returns the contents of list in a json object
+
+        POST request with json object of format
+        {
+            "data": <value to insert into stack>[,
+            "sucessor": <successor value>]
+        }
+        inserts value into list
+
+        DELETE request with json object of format {"data":<value to remove from list>} removes
+        the value from the list
+
+        If data is not presented in json format, if it is not string or number or if a successor
+        or an item to remove is not in the list a Bad Reques code is returned
+"""
+
+from data_structures import *
+from server import *
+
+DataServer(Stack, LinkedList).run()

submissions/eoneoff/data-structures-http/server/__init__.py

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+from .server import DataServer

submissions/eoneoff/data-structures-http/server/handler.py

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+from http.server import BaseHTTPRequestHandler
+import json
+import cgi
+
+class DataHandler(BaseHTTPRequestHandler):
+    def __init__(self, stack, linked_list, *args):
+        self._stack = stack
+        self._list = linked_list
+        super().__init__(*args)
+
+    def _set_headers(self):
+        self.send_response(200)
+        self.send_header('Content-type', 'application/json')
+        self.end_headers()
+
+    def do_HEAD(self):
+        self._set_headers()
+
+    @staticmethod
+    def _value_is_valid(value):
+        return type(value) == str \
+            or type(value) == int \
+            or type(value) == float
+
+    def _request_is_json(self):
+        ctype,_ = cgi.parse_header(self.headers.get('content-type'))
+        if ctype!='application/json':
+            self.send_error(400, 'Wrong content type')
+            return False
+        else: return True
+
+    def _get_request_data(self):
+        length = int(self.headers.get('content-length'))
+        return json.loads(self.rfile.read(length))
+
+    def _get_structure_type(self):
+        structure_type = self.path.split('/')[1]
+        return structure_type if structure_type  in ['stack', 'list'] else None
+
+
+    def do_GET(self):
+        if(self._get_structure_type() == 'list'):
+            self._set_headers()
+            self.wfile.write(str.encode(json.dumps({'data':self._list.show_list()})))
+
+    def do_POST(self):
+        if(self._request_is_json()):
+            data = self._get_request_data()
+            if DataHandler._value_is_valid(data['data']):
+                structure_type = self._get_structure_type()
+                if structure_type == 'stack':
+                    self._stack.push(data['data'])
+                    self.send_response(200)
+                    self.end_headers()
+                elif structure_type == 'list':
+                    successor = data.setdefault('successor')
+                    if not successor or DataHandler._value_is_valid(successor):
+                        try:
+                            self._list.insert(data['data'], successor)
+                            self.send_response(200)
+                            self.end_headers()
+                        except ValueError as err:
+                            self.send_error(400, str(err))
+                    else: self.send_error(400, 'Wrong successor format')
+            else: self.send_error(400, 'Wrong value type')
+        else: self.send_error(400, 'Wrong content type')
+
+    def do_DELETE(self):
+        structure_type = self._get_structure_type()
+        if structure_type == 'stack':
+            self._set_headers()
+            self.wfile.write(str.encode(json.dumps({'data': self._stack.pop()})))
+        elif structure_type == 'list':
+            if self._request_is_json():
+                data = self._get_request_data()
+                if DataHandler._value_is_valid(data['data']):
+                    try:
+                        self._list.remove(data['data'])
+                        self.send_response(200)
+                        self.end_headers()
+                    except ValueError as err:
+                        self.send_error(400, str(err))
+                else: self.send_error(400, 'Wrong data type')
+            else:  self.send_error(400, 'Wrong content type')

submissions/eoneoff/data-structures-http/server/server.py

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+from http.server import HTTPServer
+from .handler import DataHandler
+
+class DataServer(HTTPServer):
+    def __init__(self, queue, linked_list, host='localhost', port=8000):
+        self._queue = queue()
+        self._list = linked_list()
+        super().__init__((host, port),
+            lambda *args: DataHandler(self._queue, self._list, *args))
+
+    def run(self):
+        self.serve_forever()