Fixed CSV export when PlotDataItem uses stepMode=True

Added CSV export unit tests
Merge remote-tracking branch 'termim/csv' into develop

pyqtgraph/exporters/CSVExporter.py

@@ -52,10 +52,11 @@ class CSVExporter(Exporter):
         numRows = max([len(d[0]) for d in data])
         for i in range(numRows):
             for d in data:
-                if i < len(d[0]):
-                    fd.write(numFormat % d[0][i] + sep + numFormat % d[1][i] + sep)
-                else:
-                    fd.write(' %s %s' % (sep, sep))
+                for j in [0, 1]:
+                    if i < len(d[j]):
+                        fd.write(numFormat % d[j][i] + sep)
+                    else:
+                        fd.write(' %s' % sep)
             fd.write('\n')
         fd.close()
 

pyqtgraph/exporters/tests/test_csv.py

@@ -0,0 +1,49 @@
+"""
+SVG export test
+"""
+import pyqtgraph as pg
+import pyqtgraph.exporters
+import csv
+
+app = pg.mkQApp()
+
+def approxeq(a, b):
+    return (a-b) <= ((a + b) * 1e-6)
+
+def test_CSVExporter():
+    plt = pg.plot()
+    y1 = [1,3,2,3,1,6,9,8,4,2]
+    plt.plot(y=y1, name='myPlot')
+    
+    y2 = [3,4,6,1,2,4,2,3,5,3,5,1,3]
+    x2 = pg.np.linspace(0, 1.0, len(y2))
+    plt.plot(x=x2, y=y2)
+    
+    y3 = [1,5,2,3,4,6,1,2,4,2,3,5,3]
+    x3 = pg.np.linspace(0, 1.0, len(y3)+1)
+    plt.plot(x=x3, y=y3, stepMode=True)
+    
+    ex = pg.exporters.CSVExporter(plt.plotItem)
+    ex.export(fileName='test.csv')
+
+    r = csv.reader(open('test.csv', 'r'))
+    lines = [line for line in r]
+    header = lines.pop(0)
+    assert header == ['myPlot_x', 'myPlot_y', 'x', 'y', 'x', 'y']
+    
+    i = 0
+    for vals in lines:
+        vals = list(map(str.strip, vals))
+        assert (i >= len(y1) and vals[0] == '') or approxeq(float(vals[0]), i) 
+        assert (i >= len(y1) and vals[1] == '') or approxeq(float(vals[1]), y1[i]) 
+        
+        assert (i >= len(x2) and vals[2] == '') or approxeq(float(vals[2]), x2[i])
+        assert (i >= len(y2) and vals[3] == '') or approxeq(float(vals[3]), y2[i])
+        
+        assert (i >= len(x3) and vals[4] == '') or approxeq(float(vals[4]), x3[i])
+        assert (i >= len(y3) and vals[5] == '') or approxeq(float(vals[5]), y3[i])
+        i += 1
+    
+if __name__ == '__main__':
+    test_CSVExporter()
+