generate_reaction_templates.py 文件源码

def reassign_atom_mapping(transform):
    '''This function takes an atom-mapped reaction and reassigns 
    the atom-mapping labels (numbers) from left to right, once 
    that transform has been canonicalized.'''

    all_labels = re.findall('\:([0-9]+)\]', transform)

    # Define list of replacements which matches all_labels *IN ORDER*
    replacements = []
    replacement_dict = {}
    counter = 1
    for label in all_labels: # keep in order! this is important
        if label not in replacement_dict:
            replacement_dict[label] = str(counter)
            counter += 1
        replacements.append(replacement_dict[label])

    # Perform replacements in order
    transform_newmaps = re.sub('\:[0-9]+\]', 
        lambda match: (':' + replacements.pop(0) + ']'),
        transform)

    return transform_newmaps