Better POO using interfaces

For chapter 9

sources/marvel/marvel_06.py

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+import abc
+import hashlib
+import requests
+import shutil
+import time
+import textwrap
+import sys
+
+
+class Authorization:
+    def __init__(self, filename):
+        with open(filename, "r") as file:
+            lines = file.readlines()
+
+        if len(lines) != 2:
+            sys.exit("Incorrect api-keys file")
+
+        self.public_key = lines[0].strip()
+        self.private_key = lines[1].strip()
+
+    def generate_params(self):
+        params = dict()
+        params["apikey"] = self.public_key
+        ts = str(time.time())
+        to_hash = ts + self.private_key + self.public_key
+        hasher = hashlib.md5()
+        hasher.update(to_hash.encode())
+        digest = hasher.hexdigest()
+        params["ts"] = ts
+        params["hash"] = digest
+        return params
+
+
+class Client():
+    base_url = "http://gateway.marvel.com/v1/public"
+
+    def __init__(self, auth):
+        self.auth = auth
+
+    def make_request(self, query):
+        params = self.auth.generate_params()
+        params.update(query.params())
+        url = Client.base_url + query.path
+        response = requests.get(url, params=params)
+        status_code = response.status_code
+        if status_code != 200:
+            sys.exit("got status: " + str(status_code))
+        body = response.json()
+        result = query.extract(body)
+        return (query.to_text(result), body["attributionText"])
+
+
+class Query(metaclass=abc.ABCMeta):
+    @abc.abstractmethod
+    def params(self):
+        pass
+
+    @abc.abstractmethod
+    def path(self):
+        pass
+
+    @abc.abstractmethod
+    def extract(self, body):
+        pass
+
+    def to_text(self, result):
+        return result
+
+
+class CharacterDescription(Query):
+    path = "/characters"
+
+    def __init__(self, name):
+        self.name = name
+
+    def params(self):
+        return { "name": self.name }
+
+    def extract(self, body):
+        return body["data"]["results"][0]["description"]
+
+
+class CreatorNumberOfSeries(Query):
+    path = "/creators"
+
+    def __init__(self, first_name, last_name):
+        self.first_name = first_name
+        self.last_name = last_name
+
+    def params(self):
+        return { "firstName": self.first_name, "lastName": self.last_name }
+
+    def extract(self, body):
+        return body["data"]["results"][0]["series"]["available"]
+
+    def to_text(self, result):
+        return f"{self.first_name} {self.last_name} worked on {result} series"
+
+
+class Display:
+    def __init__(self, width=80):
+        self.width = width
+
+    def display(self, text):
+        print("\n".join(textwrap.wrap(text, width=self.width)))
+
+
+def main():
+
+    query_type = sys.argv[1]
+    if query_type == "character-description":
+        name = sys.argv[2]
+        query = CharacterDescription(name)
+    elif query_type == "creator-number-of-series":
+        first_name = sys.argv[2]
+        last_name = sys.argv[3]
+        query = CreatorNumberOfSeries(first_name, last_name)
+
+    auth = Authorization("api-keys.txt")
+    client = Client(auth)
+    text, attribution = client.make_request(query)
+
+    terminal_size = shutil.get_terminal_size()
+    columns = terminal_size.columns
+    terminal = Display(width=columns)
+
+    terminal.display(text)
+    terminal.display("---")
+    terminal.display(attribution)
+
+
+if __name__ == "__main__":
+    main()