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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def list_all_image(path, valid_exts=VALID_IMAGE_EXTS):
 """List all images under path @return unicode list """

    for filename in os.listdir(path):
        bname, ext = os.path.splitext(filename)
        if ext.lower() not in VALID_IMAGE_EXTS:
            continue
        filepath = os.path.join(path, filename)
        yield strutils.decode(filepath)