Seperate client and server of FTP (#1106)

* added sample file to transfer

* split client and server into separate files

* client and server now work in python2

* server works on python3

* client works on python3

* allow configurable ONE_CONNECTION_ONLY for testing server

* allow testing of ftp server + client

* use f-strings

* removed single letter vars

* fixed bad quote marks

* clearer file handler names

* 'with open() as' syntax

* unicode and emojis in the test data

* s -> sock

* consistent comment spacing

* remove closing formalities

* swap in and out_file

* f-string

* if __name__ == '__main__':

.travis.yml

@@ -38,7 +38,6 @@ script:
   - mypy --ignore-missing-imports .
   - pytest . --doctest-modules
       --ignore=file_transfer_protocol/ftp_send_receive.py
-      --ignore=file_transfer_protocol/ftp_client_server.py
       --ignore=machine_learning/linear_regression.py
       --ignore=machine_learning/perceptron.py
       --ignore=machine_learning/random_forest_classification/random_forest_classification.py

file_transfer_protocol/client.py

@@ -0,0 +1,23 @@
+if __name__ == '__main__':
+    import socket  # Import socket module
+
+    sock = socket.socket()  # Create a socket object
+    host = socket.gethostname()  # Get local machine name
+    port = 12312
+
+    sock.connect((host, port))
+    sock.send(b'Hello server!')
+
+    with open('Received_file', 'wb') as out_file:
+        print('File opened')
+        print('Receiving data...')
+        while True:
+            data = sock.recv(1024)
+            print(f"data={data}")
+            if not data:
+                break
+            out_file.write(data)  # Write data to a file
+
+    print('Successfully got the file')
+    sock.close()
+    print('Connection closed')

file_transfer_protocol/ftp_client_server.py

@@ -1,57 +0,0 @@
-# server
-
-import socket                   # Import socket module
-
-port = 60000                    # Reserve a port for your service.
-s = socket.socket()             # Create a socket object
-host = socket.gethostname()     # Get local machine name
-s.bind((host, port))            # Bind to the port
-s.listen(5)                     # Now wait for client connection.
-
-print('Server listening....')
-
-while True:
-    conn, addr = s.accept()     # Establish connection with client.
-    print('Got connection from', addr)
-    data = conn.recv(1024)
-    print('Server received', repr(data))
-
-    filename = 'mytext.txt'
-    with open(filename, 'rb') as f:
-        in_data = f.read(1024)
-        while in_data:
-            conn.send(in_data)
-            print('Sent ', repr(in_data))
-            in_data = f.read(1024)
-
-    print('Done sending')
-    conn.send('Thank you for connecting')
-    conn.close()
-
-
-# client side server
-
-import socket                   # Import socket module
-
-s = socket.socket()             # Create a socket object
-host = socket.gethostname()     # Get local machine name
-port = 60000                    # Reserve a port for your service.
-
-s.connect((host, port))
-s.send("Hello server!")
-
-with open('received_file', 'wb') as f:
-    print('file opened')
-    while True:
-        print('receiving data...')
-        data = s.recv(1024)
-        print('data=%s', (data))
-        if not data:
-            break
-        # write data to a file
-        f.write(data)
-
-f.close()
-print('Successfully get the file')
-s.close()
-print('connection closed')

file_transfer_protocol/mytext.txt

@@ -0,0 +1,6 @@
+Hello
+This is sample data
+«küßî»
+“ЌύБЇ”
+😀😉
+😋

file_transfer_protocol/server.py

@@ -0,0 +1,34 @@
+if __name__ == '__main__':
+    import socket  # Import socket module
+
+    ONE_CONNECTION_ONLY = True  # Set this to False if you wish to continuously accept connections
+
+    filename='mytext.txt'
+    port = 12312  # Reserve a port for your service.
+    sock = socket.socket()  # Create a socket object
+    host = socket.gethostname()  # Get local machine name
+    sock.bind((host, port))  # Bind to the port
+    sock.listen(5)  # Now wait for client connection.
+
+    print('Server listening....')
+
+    while True:
+        conn, addr = sock.accept()  # Establish connection with client.
+        print(f"Got connection from {addr}")
+        data = conn.recv(1024)
+        print(f"Server received {data}")
+
+        with open(filename,'rb') as in_file:
+            data = in_file.read(1024)
+            while (data):
+               conn.send(data)
+               print(f"Sent {data!r}")
+               data = in_file.read(1024)
+
+        print('Done sending')
+        conn.close()
+        if ONE_CONNECTION_ONLY:  # This is to make sure that the program doesn't hang while testing
+            break
+
+    sock.shutdown(1)
+    sock.close()