Create .gitattributes

And set Pyhton and text files to Unix style end of lines (lf)
Convert boxes/extents.py which was still on DOS style new lines.

.gitattributes

@@ -0,0 +1 @@
+*.py text eol=lf

boxes/extents.py

@@ -1,44 +1,44 @@
-class Extents:
-    __slots__ = "xmin ymin xmax ymax".split()
-
-    def __init__(self,xmin=float('inf'),ymin=float('inf'),xmax=float('-inf'),ymax=float('-inf')):
-        self.xmin = xmin
-        self.ymin = ymin
-        self.xmax = xmax 
-        self.ymax = ymax
-
-    def add(self,x,y):
-        self.xmin = min(self.xmin,x)
-        self.xmax = max(self.xmax,x)
-        self.ymin = min(self.ymin,y)
-        self.ymax = max(self.ymax,y)
-
-    def extend(self,l):
-        for x,y in l:
-            self.add(x,y)
-
-    def __add__(self,extent):
-        #todo: why can this happen?
-        if extent ==0: 
-            return Extents(self.xmin,self.ymin,self.xmax,self.ymax)
-        return Extents(
-            min(self.xmin,extent.xmin),min(self.ymin,extent.ymin),
-            max(self.xmax,extent.xmax),max(self.ymax,extent.ymax)
-        )
-
-    def __radd__(self,extent):
-        if extent == 0:
-            return Extents(self.xmin,self.ymin,self.xmax,self.ymax)
-        return self.__add__(extent)
-       
-    def get_width(self):
-        return self.xmax-self.xmin
-    
-    def get_height(self):
-        return self.ymax-self.ymin
-
-    width = property(get_width)
-    height = property(get_height)
-    
-    def __repr__(self):
+class Extents:
+    __slots__ = "xmin ymin xmax ymax".split()
+
+    def __init__(self,xmin=float('inf'),ymin=float('inf'),xmax=float('-inf'),ymax=float('-inf')):
+        self.xmin = xmin
+        self.ymin = ymin
+        self.xmax = xmax 
+        self.ymax = ymax
+
+    def add(self,x,y):
+        self.xmin = min(self.xmin,x)
+        self.xmax = max(self.xmax,x)
+        self.ymin = min(self.ymin,y)
+        self.ymax = max(self.ymax,y)
+
+    def extend(self,l):
+        for x,y in l:
+            self.add(x,y)
+
+    def __add__(self,extent):
+        #todo: why can this happen?
+        if extent ==0: 
+            return Extents(self.xmin,self.ymin,self.xmax,self.ymax)
+        return Extents(
+            min(self.xmin,extent.xmin),min(self.ymin,extent.ymin),
+            max(self.xmax,extent.xmax),max(self.ymax,extent.ymax)
+        )
+
+    def __radd__(self,extent):
+        if extent == 0:
+            return Extents(self.xmin,self.ymin,self.xmax,self.ymax)
+        return self.__add__(extent)
+       
+    def get_width(self):
+        return self.xmax-self.xmin
+    
+    def get_height(self):
+        return self.ymax-self.ymin
+
+    width = property(get_width)
+    height = property(get_height)
+    
+    def __repr__(self):
         return f'Extents ({self.xmin},{self.ymin})-({self.xmax},{self.ymax})'