in utils/express_utils.py [0:0]
def to_prefix_notation(str_):
"""
A simple utils method that converts the input string A(B,C(D),E) into the more
familiar EXR format: (A B (C D ) E ). One extra processing is the upper-casing of
of non-terminal nodes to match the EXR format convention.
:param str_: input string to be converted
:return: str after conversion
"""
res = []
str_ = str_.replace(')',' )').replace('(','( ').replace(',', ' ')
for word in str_.split():
if word.endswith('('):
word = '(' + word.strip('(').upper()
res.append(word)
return ' '.join(res)