Merge pull request #102 from fau-fablab/refactor-code-smells-and-unne…

…cessary-complexity

Refactor code smells and unnecessary complexity

FabLabKasse/UI/ClientDialogCode.py

@@ -22,10 +22,12 @@
 
 
 class SelectClientDialog(QtGui.QDialog, Ui_SelectClientDialog):
+
     """ GUI code for the dialog for selecting clients """
 
     def __init__(self, parent, shopping_backend):
         """ constructor for the ClientDialog
+        
         :param parent: parent GUI dialog
         :type parent: QtGui.QDialog
         :param shopping_backend: current instance of ShoppingBackend
@@ -76,12 +78,12 @@ def insertIntoLineEdit(self, char):
     def backspaceLineEdit(self):
         if self.lineEdit_pin.hasFocus():
             oldtext = self.lineEdit_pin.text()
-            if len(oldtext) > 0:
+            if oldtext:
                 self.lineEdit_pin.setText(oldtext[:-1])
                 self.lineEditPINUpdate()
         else:
             oldtext = self.lineEdit_client.text()
-            if len(oldtext) > 0:
+            if oldtext:
                 self.lineEdit_client.setText(oldtext[:-1])
                 self.lineEditClientUpdate()
 
@@ -99,7 +101,7 @@ def lineEditClientUpdate(self):
 
         # Check if client number existst and switch to client in comboBox_client
         client = self.getClient()
-        if client == None:
+        if client is None:
             self.comboBox_client.setCurrentIndex(0)
             return
 

FabLabKasse/UI/LoadFromMobileAppDialogCode.py

@@ -57,7 +57,7 @@ def __init__(self, parent, app_url):
         QtCore.QTimer.singleShot(0, lambda: self.setWindowState(QtCore.Qt.WindowMaximized))
         set_layout_items_visible(self.verticalLayout_app_download, False)
         self.pushButton_app.clicked.connect(self._show_app_download)
-        if app_url == None:
+        if app_url is None:
             self.pushButton_app.setVisible(False)
         else:
             LoadFromMobileAppDialog.set_qr_label(self.label_qr_app, app_url)

FabLabKasse/UI/PayupCashDialogCode.py

@@ -126,7 +126,7 @@ def showSuggestedDonations(self):
                 pass
                 # .disconnect() returns TypeError if currently nothing is connected to the signal
                 # http://stackoverflow.com/questions/21586643/pyqt-widget-connect-and-disconnect/21587045#21587045
-            if len(suggestedDonations) > 0:
+            if suggestedDonations:
                 donationValue = suggestedDonations.pop()
                 # functools.partial is used here instead of lambda because "donationValue" needs to be evaluated here.
                 #   when using a lambda, it would be wrongly used by-reference and get the value of the last iteration of this loop
@@ -182,7 +182,7 @@ def update(self):
                 self.state = "initCanPayout"
         elif self.state == "initCanPayout":
             pay = p.canPayout()
-            if pay != None:
+            if pay is not None:
                 [self.payoutMaximumAmount, self.payoutRemainingAmount] = pay
 
                 # all amounts under 50€ may be paid with <= n+50€

FabLabKasse/UI/PayupManualDialogCode.py

@@ -65,7 +65,7 @@ def insertIntoLineEdit(self, char):
 
     def backspaceLineEdit(self):
         oldtext = self.lineEdit.text()
-        if len(oldtext) > 0:
+        if oldtext:
             self.lineEdit.setText(oldtext[:-3])
             self.lineEditUpdated()
 

FabLabKasse/cashPayment/client/PaymentDeviceClient.py

@@ -130,7 +130,7 @@ def poll(self):
                 cmd = None
             else:
                 raise Exception("unknown status")
-            if cmd == None:
+            if cmd is None:
                 return
             print "SEND CMD: " + cmd  # +"\n"
             self.process.write(cmd + "\n")
@@ -139,10 +139,10 @@ def poll(self):
             self.lastResponseTime = monotonic_time.monotonic()  # get monotonic time. until python 3.3 we have to use this extra module because time.monotonic() is not available in older versions.
 
         response = self.process.readline()
-        if response == None and self.waitingForResponse \
+        if response is None and self.waitingForResponse \
                 and monotonic_time.monotonic() - self.lastResponseTime > 50:
             raise Exception("device {} server timeout (>50sec)".format(self))
-        if response != None:
+        if response is not None:
             print "got response: '" + response + "'"
             assert self.waitingForResponse
             self.waitingForResponse = False

FabLabKasse/cashPayment/client/PaymentDevicesManager.py

@@ -181,7 +181,7 @@ def _canPayout_total(self, canPayoutAmounts):
         :return: [totalMaximumRequest, totalRemaining]
         """
 
-        if len(canPayoutAmounts) == 0:
+        if not canPayoutAmounts:
             return [0, 0]
         [totalMaximumRequest, totalRemaining] = canPayoutAmounts[0]
         for [maximumRequest, remainingAmount] in canPayoutAmounts[1:]:
@@ -298,7 +298,7 @@ def formatCent(x):
             requested = self.requestedPayin
         elif self.mode.startswith("payout"):
             requested = self.requestedPayout
-        if requested != None:
+        if requested is not None:
             text += u":\n{} von {} ".format(formatCent(totalSum), formatCent(requested))
         if self.mode.startswith("payin"):
             text += "bezahlt (maximal " + formatCent(self.maximumPayin) + ")"
@@ -418,23 +418,23 @@ def wait():
     while p.startingUp():
         wait()
     pay = None
-    while pay == None:
+    while pay is None:
         wait()
         pay = p.canPayout()
     print pay
     print "Es dürfen maximal {} Cent gezahlt werden. Ein Rest-Rückgeld von unter {} Cent wird nicht zurückgegeben!".format(pay[0], pay[1])
     shouldPay = 4213
     p.payin(shouldPay, shouldPay + pay[0])
     received = None
-    while received == None:
+    while received is None:
         received = p.getFinalAmount()
         wait()
     print "Geld erhalten: {}".format(received)
     p.poll()
     if received > shouldPay:
         p.payout(received - shouldPay)
     paidOut = None
-    while paidOut == None:
+    while paidOut is None:
         paidOut = p.getFinalAmount()
         wait()
     paidOut = -paidOut

FabLabKasse/cashPayment/server/NV11/NV11Device.py

@@ -233,10 +233,10 @@ def flushRead(self):
         while self.ser.inWaiting() > 0:
             self.warn("flushing serial read buffer")
             self.ser.read(self.ser.inWaiting())
-        if len(self.rawBuffer) > 0:
+        if self.rawBuffer:
             self.warn("flushing raw input buffer")
             self.rawBuffer = []
-        if len(self.buffer) > 0:
+        if self.buffer:
             self.warn("flushing input buffer")
             self.buffer = []
 
@@ -254,7 +254,7 @@ def read(self):
 
         # read bytes for de-stuffing
 
-        while len(self.rawBuffer) > 0:
+        while self.rawBuffer:
             if self.rawBuffer[0] == 0x7F:
                 # the STX byte needs special care (byte-stuffing needs to be reversed)
                 if len(self.rawBuffer) == 1:
@@ -283,7 +283,7 @@ def read(self):
 
         # attention, python subranging is a bit strange: array[a:b] returns array[a] ... array[b-1]   (not including b!)
 
-        while len(self.buffer) > 0:
+        while self.buffer:
             self.debug2("buffer: " + hex(self.buffer))
 
             # check validity of packet
@@ -350,7 +350,7 @@ class Response(object):
         }
 
         def __init__(self, data):
-            if len(data) == 0:
+            if not data:
                 # empty response AFTER decoding
                 self.status = -1
                 self.data = []

FabLabKasse/cashPayment/server/exampleServer.py

@@ -19,7 +19,7 @@
 #  The text of the license conditions can be read at
 #  <http://www.gnu.org/licenses/>.
 
-from .cashServer import *
+from .cashServer import CashServer
 import random
 
 

FabLabKasse/cashPayment/server/helpers/banknote_stack_helper.py

@@ -57,7 +57,7 @@ def _would_stack_from_payout(self, payout_stack, requested_payout):
             True if it might be helpful. The driver should do further checks if it is really necessary.
         :rtype: bool
         """
-        if len(payout_stack) == 0:
+        if not payout_stack:
             # no notes to payout
             return False
         if requested_payout < min(payout_stack):
@@ -82,7 +82,7 @@ def _simulate_simple_payout(self, payout_stack, requested_payout):
         """
         simulated_payout = 0
         payout_stack = copy.copy(payout_stack)
-        while len(payout_stack) > 0:
+        while payout_stack:
             if simulated_payout + payout_stack[-1] <= requested_payout:
                 # would pay out note, if it is not too large
                 simulated_payout += payout_stack[-1]
@@ -130,7 +130,7 @@ def get_next_payout_action(self, payout_stack, requested_payout):
         """which action should be taken next?
         (see the documentation for BanknoteStackHelper for more context information)
         """
-        if len(payout_stack) == 0:
+        if not payout_stack:
             return "stop"
         if self._forced_stacking_is_helpful(payout_stack, requested_payout) and self._would_stack_from_payout(payout_stack, requested_payout):
             return "stack"
@@ -145,7 +145,7 @@ def get_next_payout_action(self, payout_stack, requested_payout):
 
     def can_payout(self, payout_stack):
         """ implementation for CashServer.getCanPayout()"""
-        if len(payout_stack) == 0:
+        if not payout_stack:
             # no notes available at all
             return self.accepted_rest
 
@@ -210,7 +210,7 @@ def unittest_payout_forced_stacking(self, random_generator):
         origpayout_stack = copy.deepcopy(payout_stack)
 
         simulated_payout = 0
-        while len(payout_stack) > 0:
+        while payout_stack:
             if self._forced_stacking_is_helpful(payout_stack, requested_payout):
                 pass
                 # print("extra stack away useful")

FabLabKasse/cashPayment/server/mdbCash/mdb.py

@@ -120,7 +120,7 @@ def flushRead(self):
         while self.ser.inWaiting() > 0:
             self.warn("flushing serial read buffer")
             self.ser.read(self.ser.inWaiting())
-        if len(self.buffer) > 0:
+        if self.buffer:
             self.warn("flushing input buffer")
             self.buffer = ""
 
@@ -144,7 +144,7 @@ def read(self):
         else:
             pass
             # logging.debug("not read:" + self.ser.read())
-        if len(self.buffer) > 0:
+        if self.buffer:
             logging.debug("buffer: {}".format(self.buffer.__repr__()))
         if not ("\n" in self.buffer):
             # we have not yet received a full response
@@ -187,7 +187,7 @@ def checksum(self, data):
     # raises BusError or InterfaceHardwareError, see send()
     # returns valid data
     def cmd(self, command, data=None):
-        if data == None:
+        if data is None:
             data = []
         assert 0 <= command < 8
         bytes = [self.addr << 3 | command] + data
@@ -203,11 +203,11 @@ def cmd(self, command, data=None):
                     # timeout for interface board: 1sec
                     time.sleep(0.1)
                     resp = self.read()  # possibly raises BusError (will be caught below) or InterfaceHardwareError (will not be caught)
-                    if resp != None:
+                    if resp is not None:
                         resp = resp.strip()
                         logging.debug("resp: " + resp.__repr__())
                         break
-                if resp == None:
+                if resp is None:
                     raise InterfaceHardwareError("interface timeout")
                 else:
                     break
@@ -216,7 +216,7 @@ def cmd(self, command, data=None):
                 logging.debug("bus error,  resending")
                 time.sleep(1)
                 continue
-        if resp == None:
+        if resp is None:
             raise BusError("no successful response after 3 retries")
         responseData = []
         # convert response (hex-string) to a byte array
@@ -242,7 +242,7 @@ def extensionCmd(self, data):
             # timeout for interface board: 1sec
             time.sleep(0.1)
             resp = self.read()  # possibly raises BusError or InterfaceHardwareError (both will not be caught)
-            if resp != None:
+            if resp is not None:
                 resp = resp.strip()
                 logging.debug("resp: " + resp.__repr__())
                 return resp
@@ -313,7 +313,7 @@ def getBits(byte, lowest, highest):  # cut out bits lowest...highest (including
         status = {"manuallyDispensed": [], "accepted": [], "busy": False}
         if data == [MdbCashDevice.ACK]:
             return status
-        while len(data) > 0:
+        while data:
             # parse status response
             if data[0] & 1 << 7:
                 # coin dispensed because of MANUAL! REQUEST (by pressing the button at the changer device itself)
@@ -510,15 +510,15 @@ def _getPossiblePayout(v, t):
         # go through the coins from large to small
         for [index, value] in v:
             n = t[index]["count"]
-            if previousCoinValue != None and n * value < previousCoinValue:
+            if previousCoinValue is not None and n * value < previousCoinValue:
                 # we dont have enough of this coin to "split" one previous coin
                 continue
-            if previousCoinValue == None:
+            if previousCoinValue is None:
                 previousCoinValue = 0
             totalAmount += n * value - previousCoinValue
             previousCoinValue = value
 
-        if previousCoinValue == None:
+        if previousCoinValue is None:
             return [0, 0]
 
         return [totalAmount, previousCoinValue]

FabLabKasse/gui.py

@@ -302,13 +302,11 @@ def restart(self):
         # trigger reboot ('sudo reboot' will be executed by run.py)
         result = dialog.clickedButton()
         if result == rebootButton:
-            f = open("./reboot-now", "w")
-            f.write("42")
-            f.close()
+            with open("./reboot-now", "w") as f:
+                f.write("42")
         elif result == shutdownButton:
-            f = open("./shutdown-now", "w")
-            f.write("42")
-            f.close()
+            with open("./shutdown-now", "w") as f:
+                f.write("42")
         logging.info("exiting because of restart request")
         self.close()
 
@@ -511,7 +509,7 @@ def updateProductsAndCategories(self, categories=None, products=None, category_p
             for c in category_path[:-1]:
                 self._add_to_category_path(c.name, c.categ_id, bold=False)
             # make last button with bold text
-            if len(category_path) > 0:
+            if category_path:
                 self._add_to_category_path(category_path[-1].name, category_path[-1].categ_id, bold=True)
 
         # set "all products" button to bold if the root category is selected
@@ -678,7 +676,7 @@ def insertIntoLineEdit(self, char):
 
     def backspaceLineEdit(self):
         oldtext = self.lineEdit.text()
-        if len(oldtext) > 0:
+        if oldtext:
             self.lineEdit.setText(oldtext[:-1])
             self.on_lineEdit_changed()
 
@@ -816,7 +814,7 @@ def insertIntoLineEdit_Suche(self, char):
 
     def backspaceLineEdit_Suche(self):
         oldtext = self.lineEdit_Suche.text()
-        if len(oldtext) > 0:
+        if oldtext:
             self.lineEdit_Suche.setText(oldtext[:-1])
         self.lineEdit_Suche.setFocus()
         self.searchItems(preview=True)

FabLabKasse/scripts/logWatchAndCleanup.py

@@ -74,7 +74,7 @@ def isWarningLine(line):
             if isOldUnzippedLog:
                 assert subprocess.call(["gzip", f]) == 0,  "calling gzip failed"
 
-    if len(errorLines) == 0:
+    if not errorLines:
         sys.exit(0)
 
     print("Hi, this is FabLabKasse/scripts/logWatch.sh.\nThere were warnings or errors in the recent logfile.\nPrinting the recent {} ones per file:\n".format(MAX_ERRORS_PER_LOG))

FabLabKasse/shopping/backend/abstract.py

@@ -198,7 +198,7 @@ class OrderLine(object):
     def __init__(self, order_line_id, qty, unit, name, price_per_unit, price_subtotal, delete_if_zero_qty=True):
 
         self.order_line_id = order_line_id
-        if order_line_id == None:
+        if order_line_id is None:
             self.order_line_id = next(_id_counter)  # may cause problems after ca. 2**30 calls because QVariant in gui somewhere converts values to int32. but who cares...
         self.qty = qty
         self.unit = unit

FabLabKasse/shopping/backend/legacy_offline_kassenbuch_tools/exportConsumptionMoney.py

@@ -85,7 +85,7 @@ def printFiltered(consumption,  search=None, regexp=None, scaleFactor=1, ignoreC
        """
     sumFiltered = 0
 
-    if search == None:
+    if search is None:
         # filter by regexp
         search = ""
         filterStr = regexp