Fix ResourceWarning: unclosed file

ciphers/rsa_cipher.py

@@ -80,9 +80,8 @@ def decryptMessage(encryptedBlocks, messageLength, key, blockSize=DEFAULT_BLOCK_
 
 
 def readKeyFile(keyFilename):
-    fo = open(keyFilename)
-    content = fo.read()
-    fo.close()
+    with open(keyFilename) as fo:
+        content = fo.read()
     keySize, n, EorD = content.split(',')
     return (int(keySize), int(n), int(EorD))
 
@@ -98,16 +97,15 @@ def encryptAndWriteToFile(messageFilename, keyFilename, message, blockSize=DEFAU
         encryptedBlocks[i] = str(encryptedBlocks[i])
     encryptedContent = ','.join(encryptedBlocks)
     encryptedContent = '%s_%s_%s' % (len(message), blockSize, encryptedContent)
-    fo = open(messageFilename, 'w')
-    fo.write(encryptedContent)
-    fo.close()
+    with open(messageFilename, 'w') as fo:
+        fo.write(encryptedContent)
     return encryptedContent
 
 
 def readFromFileAndDecrypt(messageFilename, keyFilename):
     keySize, n, d = readKeyFile(keyFilename)
-    fo = open(messageFilename)
-    content = fo.read()
+    with open(messageFilename) as fo:
+        content = fo.read()
     messageLength, blockSize, encryptedMessage = content.split('_')
     messageLength = int(messageLength)
     blockSize = int(blockSize)

ciphers/transposition_cipher_encrypt_decrypt_file.py

@@ -19,15 +19,16 @@ def main():
 
     startTime = time.time()
     if mode.lower().startswith('e'):
-        content = open(inputFile).read()
+        with open(inputFile) as f:
+            content = f.read()
         translated = transCipher.encryptMessage(key, content)
     elif mode.lower().startswith('d'):
-        content = open(outputFile).read()
+        with open(outputFile) as f:
+            content = f.read()
         translated =transCipher .decryptMessage(key, content)
 
-    outputObj = open(outputFile, 'w')
-    outputObj.write(translated)
-    outputObj.close()
+    with open(outputFile, 'w') as outputObj:
+        outputObj.write(translated)
 
     totalTime = round(time.time() - startTime, 2)
     print(('Done (', totalTime, 'seconds )'))

file_transfer_protocol/ftp_client_server.py

@@ -17,13 +17,12 @@
     print('Server received', repr(data))
 
     filename = 'mytext.txt'
-    f = open(filename, 'rb')
-    in_data = f.read(1024)
-    while (in_data):
-       conn.send(in_data)
-       print('Sent ', repr(in_data))
-       in_data = f.read(1024)
-    f.close()
+    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')

file_transfer_protocol/ftp_send_receive.py

@@ -20,10 +20,9 @@
 
 def ReceiveFile():
 	FileName = 'example.txt'   """ Enter the location of the file """
-	LocalFile = open(FileName, 'wb')
-	ftp.retrbinary('RETR ' + FileName, LocalFile.write, 1024)
+	with open(FileName, 'wb') as LocalFile:
+		ftp.retrbinary('RETR ' + FileName, LocalFile.write, 1024)
 	ftp.quit()
-	LocalFile.close()
 
 """
 	The file which will be sent via the FTP server
@@ -32,5 +31,6 @@ def ReceiveFile():
 
 def SendFile():
 	FileName = 'example.txt'   """ Enter the name of the file """
-	ftp.storbinary('STOR ' + FileName, open(FileName, 'rb'))
+	with open(FileName, 'rb') as LocalFile:
+		ftp.storbinary('STOR ' + FileName, LocalFile)
 	ftp.quit()

hashes/sha1.py

@@ -137,7 +137,8 @@ def main():
     input_string = args.input_string
     #In any case hash input should be a bytestring
     if args.input_file:
-        hash_input = open(args.input_file, 'rb').read()
+        with open(args.input_file, 'rb') as f:
+            hash_input = f.read()
     else:
         hash_input = bytes(input_string, 'utf-8')
     print(SHA1Hash(hash_input).final_hash())

other/anagrams.py

@@ -4,7 +4,8 @@
 start_time = time.time()
 print('creating word list...')
 path = os.path.split(os.path.realpath(__file__))
-word_list = sorted(list(set([word.strip().lower() for word in open(path[0] + '/words')])))
+with open(path[0] + '/words') as f:
+    word_list = sorted(list(set([word.strip().lower() for word in f])))
 
 def signature(word):
     return ''.join(sorted(word))

other/detecting_english_programmatically.py

@@ -5,11 +5,10 @@
 
 def loadDictionary():
     path = os.path.split(os.path.realpath(__file__))
-    dictionaryFile = open(path[0] + '/Dictionary.txt')
     englishWords = {}
-    for word in dictionaryFile.read().split('\n'):
-        englishWords[word] = None
-    dictionaryFile.close()
+    with open(path[0] + '/Dictionary.txt') as dictionaryFile:
+        for word in dictionaryFile.read().split('\n'):
+            englishWords[word] = None
     return englishWords
 
 ENGLISH_WORDS = loadDictionary()

searches/tabu_search.py

@@ -45,24 +45,23 @@ def generate_neighbours(path):
     the node 'c' with distance 18, the node 'd' with distance 22 and the node 'e' with distance 26.
 
     """
-    f = open(path, "r")
 
     dict_of_neighbours = {}
 
-    for line in f:
-        if line.split()[0] not in dict_of_neighbours:
-            _list = list()
-            _list.append([line.split()[1], line.split()[2]])
-            dict_of_neighbours[line.split()[0]] = _list
-        else:
-            dict_of_neighbours[line.split()[0]].append([line.split()[1], line.split()[2]])
-        if line.split()[1] not in dict_of_neighbours:
-            _list = list()
-            _list.append([line.split()[0], line.split()[2]])
-            dict_of_neighbours[line.split()[1]] = _list
-        else:
-            dict_of_neighbours[line.split()[1]].append([line.split()[0], line.split()[2]])
-    f.close()
+    with open(path) as f:
+        for line in f:
+            if line.split()[0] not in dict_of_neighbours:
+                _list = list()
+                _list.append([line.split()[1], line.split()[2]])
+                dict_of_neighbours[line.split()[0]] = _list
+            else:
+                dict_of_neighbours[line.split()[0]].append([line.split()[1], line.split()[2]])
+            if line.split()[1] not in dict_of_neighbours:
+                _list = list()
+                _list.append([line.split()[0], line.split()[2]])
+                dict_of_neighbours[line.split()[1]] = _list
+            else:
+                dict_of_neighbours[line.split()[1]].append([line.split()[0], line.split()[2]])
 
     return dict_of_neighbours
 
@@ -84,16 +83,15 @@ def generate_first_solution(path, dict_of_neighbours):
 
     """
 
-    f = open(path, "r")
-    start_node = f.read(1)
+    with open(path) as f:
+        start_node = f.read(1)
     end_node = start_node
 
     first_solution = []
 
     visiting = start_node
 
     distance_of_first_solution = 0
-    f.close()
     while visiting not in first_solution:
         minim = 10000
         for k in dict_of_neighbours[visiting]:

sorts/external-sort.py

@@ -15,31 +15,29 @@ def __init__(self, filename):
 
     def write_block(self, data, block_number):
         filename = self.BLOCK_FILENAME_FORMAT.format(block_number)
-        file = open(filename, 'w')
-        file.write(data)
-        file.close()
+        with open(filename, 'w') as file:
+            file.write(data)
         self.block_filenames.append(filename)
 
     def get_block_filenames(self):
         return self.block_filenames
 
     def split(self, block_size, sort_key=None):
-        file = open(self.filename, 'r')
         i = 0
+        with open(self.filename) as file:
+            while True:
+                lines = file.readlines(block_size)
 
-        while True:
-            lines = file.readlines(block_size)
+                if lines == []:
+                    break
 
-            if lines == []:
-                break
+                if sort_key is None:
+                    lines.sort()
+                else:
+                    lines.sort(key=sort_key)
 
-            if sort_key is None:
-                lines.sort()
-            else:
-                lines.sort(key=sort_key)
-
-            self.write_block(''.join(lines), i)
-            i += 1
+                self.write_block(''.join(lines), i)
+                i += 1
 
     def cleanup(self):
         map(lambda f: os.remove(f), self.block_filenames)
@@ -74,6 +72,7 @@ def refresh(self):
 
                 if self.buffers[i] == '':
                     self.empty.add(i)
+                    self.files[i].close()
 
         if len(self.empty) == self.num_buffers:
             return False
@@ -92,12 +91,11 @@ def __init__(self, merge_strategy):
         self.merge_strategy = merge_strategy
 
     def merge(self, filenames, outfilename, buffer_size):
-        outfile = open(outfilename, 'w', buffer_size)
         buffers = FilesArray(self.get_file_handles(filenames, buffer_size))
-
-        while buffers.refresh():
-            min_index = self.merge_strategy.select(buffers.get_dict())
-            outfile.write(buffers.unshift(min_index))
+        with open(outfilename, 'w', buffer_size) as outfile:
+            while buffers.refresh():
+                min_index = self.merge_strategy.select(buffers.get_dict())
+                outfile.write(buffers.unshift(min_index))
 
     def get_file_handles(self, filenames, buffer_size):
         files = {}

strings/min_cost_string_conversion.py

@@ -73,50 +73,49 @@ def assemble_transformation(ops, i, j):
 	m = len(operations)
 	n = len(operations[0])
 	sequence = assemble_transformation(operations, m-1, n-1)
-
-	file = open('min_cost.txt', 'w')
 
 	string = list('Python')
 	i = 0
 	cost = 0
-	for op in sequence:
-		print(''.join(string))
-
-		if op[0] == 'C':
-			file.write('%-16s' % 'Copy %c' % op[1])
-			file.write('\t\t\t' + ''.join(string))
-			file.write('\r\n')
-
-			cost -= 1
-		elif op[0] == 'R':
-			string[i] = op[2]
-
-			file.write('%-16s' % ('Replace %c' % op[1] + ' with ' + str(op[2])))
-			file.write('\t\t' + ''.join(string))
-			file.write('\r\n')
-
-			cost += 1
-		elif op[0] == 'D':
-			string.pop(i)
-
-			file.write('%-16s' % 'Delete %c' % op[1])
-			file.write('\t\t\t' + ''.join(string))
-			file.write('\r\n')
-
-			cost += 2
-		else:
-			string.insert(i, op[1])
+
+	with open('min_cost.txt', 'w') as file:
+		for op in sequence:
+			print(''.join(string))
+
+			if op[0] == 'C':
+				file.write('%-16s' % 'Copy %c' % op[1])
+				file.write('\t\t\t' + ''.join(string))
+				file.write('\r\n')
+
+				cost -= 1
+			elif op[0] == 'R':
+				string[i] = op[2]
+
+				file.write('%-16s' % ('Replace %c' % op[1] + ' with ' + str(op[2])))
+				file.write('\t\t' + ''.join(string))
+				file.write('\r\n')
+
+				cost += 1
+			elif op[0] == 'D':
+				string.pop(i)
+
+				file.write('%-16s' % 'Delete %c' % op[1])
+				file.write('\t\t\t' + ''.join(string))
+				file.write('\r\n')
+
+				cost += 2
+			else:
+				string.insert(i, op[1])
 
-			file.write('%-16s' % 'Insert %c' % op[1])
-			file.write('\t\t\t' + ''.join(string))
-			file.write('\r\n')
-
-			cost += 2
+				file.write('%-16s' % 'Insert %c' % op[1])
+				file.write('\t\t\t' + ''.join(string))
+				file.write('\r\n')
+				
+				cost += 2
 
-		i += 1
+			i += 1
 
-	print(''.join(string))
-	print('Cost: ', cost)
-
-	file.write('\r\nMinimum cost: ' + str(cost))
-	file.close()
+		print(''.join(string))
+		print('Cost: ', cost)
+
+		file.write('\r\nMinimum cost: ' + str(cost))