diff --git a/.gitignore b/.gitignore
index c69b9ca..78b8d01 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 *.py[cod]
+env
 
 # C extensions
 *.so
diff --git a/examples/demo_all.py b/examples/demo_all.py
index 1d426e2..8886a4c 100644
--- a/examples/demo_all.py
+++ b/examples/demo_all.py
@@ -283,7 +283,7 @@
 xdata = range(nb_element)
 xdata = list(map(lambda x: start_time + x * 1000000000, xdata))
 ydata = [i + random.randint(1, 10) for i in range(nb_element)]
-ydata2 = map(lambda x: x * 2, ydata)
+ydata2 = list(map(lambda x: x * 2, ydata))
 
 tooltip_date = "%d %b %Y %H:%M:%S %p"
 extra_serie = {"tooltip": {"y_start": "There are ", "y_end": " calls"},
diff --git a/examples/multiBarChart_date.py b/examples/multiBarChart_date.py
index 19eff29..a4b6517 100644
--- a/examples/multiBarChart_date.py
+++ b/examples/multiBarChart_date.py
@@ -27,7 +27,7 @@
 xdata = range(nb_element)
 xdata = list(map(lambda x: start_time + x * 100000000, xdata))
 ydata = [i + random.randint(1, 10) for i in range(nb_element)]
-ydata2 = map(lambda x: x * 2, ydata)
+ydata2 = list(map(lambda x: x * 2, ydata))
 
 tooltip_date = "%d %b %Y %H:%M:%S %p"
 extra_serie = {"tooltip": {"y_start": "There are ", "y_end": " calls"},