Wait until function finish executing in Python
<p>I am new to Python</p>

<p>I have the codes below:</p>

<p>Inside my for there is another for loop then that 2nd for loop calls a function that does another for loop.  Now I want the 2nd for loop to wait until the 3rd loops finish its job.  How to do that?</p>

<p>Thanks</p>

<pre><code>def GetArea(img):
    os.chdir("C:\RJC Files\Thesis\Biometrics Thesis\Raw Data\Pics\PickedImages\\" + str(x) + "\\Process")
    for file2 in glob.glob("*.png"):
        # DO SOMETHING 
        # TAKE SOMETIME TO FINISH HERE.
-----------------------------------------------------------     
for x in range(1, 2):
    os.chdir("C:\RJC Files\Thesis\Biometrics Thesis\Raw Data\Pics\PickedImages\\" + str(x) + "\\Area")
    for file in glob.glob("*.png"):
        img = cv2.imread(file, 0)

        GetArea(img)
</code></pre>