Rename functions to pep8 naming conventions

Ch03/treePlotter.py

@@ -3,82 +3,90 @@
 
 @author: Peter Harrington
 """
-import matplotlib.pyplot as plt
+import matplotlib.pyplot as plot
 
 
-decisionNode = dict(boxstyle="sawtooth", fc="0.8")
-leafNode = dict(boxstyle="round4", fc="0.8")
+decision_node = dict(boxstyle="sawtooth", fc="0.8")
+leaf_node = dict(boxstyle="round4", fc="0.8")
 arrow_args = dict(arrowstyle="<-")
 
 
-def getNumLeafs(myTree):
+def get_num_leafs(myTree):
     numLeafs = 0
     firstStr = myTree.keys()[0]
     secondDict = myTree[firstStr]
     for key in secondDict.keys():
         if type(secondDict[key]).__name__=='dict':#test to see if the nodes are dictonaires, if not they are leaf nodes
-            numLeafs += getNumLeafs(secondDict[key])
+            numLeafs += get_num_leafs(secondDict[key])
         else:   numLeafs +=1
     return numLeafs
 
 
-def getTreeDepth(myTree):
+def get_tree_depth(myTree):
     maxDepth = 0
     firstStr = myTree.keys()[0]
     secondDict = myTree[firstStr]
     for key in secondDict.keys():
         if type(secondDict[key]).__name__=='dict':#test to see if the nodes are dictonaires, if not they are leaf nodes
-            thisDepth = 1 + getTreeDepth(secondDict[key])
+            thisDepth = 1 + get_tree_depth(secondDict[key])
         else:   thisDepth = 1
         if thisDepth > maxDepth: maxDepth = thisDepth
     return maxDepth
 
 
-def plotNode(nodeTxt, centerPt, parentPt, nodeType):
-    createPlot.ax1.annotate(nodeTxt, xy=parentPt,  xycoords='axes fraction',
+def plot_node(nodeTxt, centerPt, parentPt, nodeType):
+    create_plot.ax1.annotate(nodeTxt, xy=parentPt,  xycoords='axes fraction',
              xytext=centerPt, textcoords='axes fraction',
-             va="center", ha="center", bbox=nodeType, arrowprops=arrow_args )
+             va="center", ha="center", bbox=nodeType, arrowprops=arrow_args)
 
 
-def plotMidText(cntrPt, parentPt, txtString):
+def plot_mid_text(cntrPt, parentPt, txtString):
     xMid = (parentPt[0]-cntrPt[0])/2.0 + cntrPt[0]
     yMid = (parentPt[1]-cntrPt[1])/2.0 + cntrPt[1]
-    createPlot.ax1.text(xMid, yMid, txtString)
+    create_plot.ax1.text(xMid, yMid, txtString)
 
 
-def plotTree(myTree, parentPt, nodeTxt):#if the first key tells you what feat was split on
-    numLeafs = getNumLeafs(myTree)  #this determines the x width of this tree
-    depth = getTreeDepth(myTree)
+def plot_tree(myTree, parentPt, nodeTxt):#if the first key tells you what feat was split on
+    numLeafs = get_num_leafs(myTree)  #this determines the x width of this tree
     firstStr = myTree.keys()[0]     #the text label for this node should be this
-    cntrPt = (plotTree.xOff + (1.0 + float(numLeafs))/2.0/plotTree.totalW, plotTree.yOff)
-    plotMidText(cntrPt, parentPt, nodeTxt)
-    plotNode(firstStr, cntrPt, parentPt, decisionNode)
+    cntrPt = (plot_tree.xOff + (1.0 + float(numLeafs))/2.0/plot_tree.totalW, plot_tree.yOff)
+    plot_mid_text(cntrPt, parentPt, nodeTxt)
+    plot_node(firstStr, cntrPt, parentPt, decision_node)
     secondDict = myTree[firstStr]
-    plotTree.yOff = plotTree.yOff - 1.0/plotTree.totalD
+    plot_tree.yOff = plot_tree.yOff - 1.0/plot_tree.totalD
     for key in secondDict.keys():
         if type(secondDict[key]).__name__=='dict':#test to see if the nodes are dictonaires, if not they are leaf nodes
-            plotTree(secondDict[key],cntrPt,str(key))        #recursion
+            plot_tree(secondDict[key],cntrPt,str(key))        #recursion
         else:   #it's a leaf node print the leaf node
-            plotTree.xOff = plotTree.xOff + 1.0/plotTree.totalW
-            plotNode(secondDict[key], (plotTree.xOff, plotTree.yOff), cntrPt, leafNode)
-            plotMidText((plotTree.xOff, plotTree.yOff), cntrPt, str(key))
-    plotTree.yOff = plotTree.yOff + 1.0/plotTree.totalD
+            plot_tree.xOff = plot_tree.xOff + 1.0/plot_tree.totalW
+            plot_node(secondDict[key], (plot_tree.xOff, plot_tree.yOff), cntrPt, leaf_node)
+            plot_mid_text((plot_tree.xOff, plot_tree.yOff), cntrPt, str(key))
+    plot_tree.yOff = plot_tree.yOff + 1.0/plot_tree.totalD
 
 
-def createPlot(inTree):
-    fig = plt.figure(1, facecolor='white')
+def create_plot(inTree):
+    fig = plot.figure(1, facecolor='white')
     fig.clf()
     axprops = dict(xticks=[], yticks=[])
-    createPlot.ax1 = plt.subplot(111, frameon=False, **axprops)    #no ticks
-    plotTree.totalW = float(getNumLeafs(inTree))
-    plotTree.totalD = float(getTreeDepth(inTree))
-    plotTree.xOff = -0.5/plotTree.totalW; plotTree.yOff = 1.0;
-    plotTree(inTree, (0.5,1.0), '')
-    plt.show()
+    create_plot.ax1 = plot.subplot(111, frameon=False, **axprops)    #no ticks
+    plot_tree.totalW = float(get_num_leafs(inTree))
+    plot_tree.totalD = float(get_tree_depth(inTree))
+    plot_tree.xOff = -0.5/plot_tree.totalW; plot_tree.yOff = 1.0;
+    plot_tree(inTree, (0.5,1.0), '')
+    plot.show()
 
 
-def retrieveTree(i):
+def retrieve_tree(i):
     listOfTrees =[{'no surfacing': {0: 'no', 1: {'flippers': {0: 'no', 1: 'yes'}}}},
                   {'no surfacing': {0: 'no', 1: {'flippers': {0: {'head': {0: 'no', 1: 'yes'}}, 1: 'no'}}}}
                   ]
     return listOfTrees[i]
+
+
+def main():
+    tree = retrieve_tree(1)
+    create_plot(tree)
+
+
+if __name__ == '__main__':
+    main()