Initial commit

Solutions/8_6/cofollow.py

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+# cofollow.py
+import os
+import time
+import csv
+
+def follow(filename,target):
+    with open(filename,"r") as f:
+        f.seek(0,os.SEEK_END)
+        while True:
+            line = f.readline()
+            if line != '':
+                target.send(line)
+            else:
+                time.sleep(0.1)
+
+def receive(expected_type):
+    msg = yield
+    assert isinstance(msg, expected_type), 'Expected type %s' % (expected_type)
+    return msg
+
+# Decorator for coroutines
+from functools import wraps
+
+def consumer(func):
+    @wraps(func)
+    def start(*args,**kwargs):
+        f = func(*args,**kwargs)
+        f.send(None)
+        return f
+    return start
+
+# Sample coroutine
+@consumer
+def printer():
+    while True:
+        item = yield from receive(object)
+        print(item)
+
+# Example use.  
+if __name__ == '__main__':
+    follow('../../Data/stocklog.csv', printer())