pushing new solution...

Microsoft_Problems/Microsoft_Problem_08.py

@@ -0,0 +1,40 @@
+"""
+This problem was asked Microsoft.
+
+Using a read7() method that returns 7 characters from a file, implement readN(n) which reads n characters.
+
+For example, given a file with the content “Hello world”, three read7() returns “Hello w”, “orld” and then “”.
+"""
+
+
+class MyFile:
+    def __init__(self, contents):
+        self.contents = contents
+        self.offset = 0
+        self.buffer = ""
+
+    def read_7(self):
+        start = self.offset
+        end = min(self.offset + 7, len(self.contents))
+        self.offset = end
+        return self.contents[start:end].strip()
+
+    def read_n(self, n):
+        while len(self.buffer) < n:
+            extra_chars = self.read_7()
+            if not extra_chars:
+                break
+            self.buffer += extra_chars
+        n_chars = self.buffer[:n]
+        self.buffer = self.buffer[n:]
+        return n_chars.strip()
+
+
+f = MyFile('Hello world')
+assert f.read_7() == "Hello w"
+assert f.read_7() == "orld"
+assert f.read_7() == ""
+
+f = MyFile("Hello world")
+assert f.read_n(8) == "Hello wo"
+assert f.read_n(8) == "rld"