I want to plot a decision tree of a random forest. So, i create the following code:

```
clf = RandomForestClassifier(n_estimators=100)
import pydotplus
import six
from sklearn import tree
dotfile = six.StringIO()
i_tree = 0
for tree_in_forest in clf.estimators_:
if (i_tree <1):        
    tree.export_graphviz(tree_in_forest, out_file=dotfile)
    pydotplus.graph_from_dot_data(dotfile.getvalue()).write_png('dtree'+ str(i_tree) +'.png')
    i_tree = i_tree + 1

```

But it doesn't generate anything..
Have you an idea how to plot a decision tree from random forest?