import re


def populate_format(entry, sformat):
    """
    replace entry keys in format with corresponding values

    Given:
    (1) entry   = { "actions" : "words", "words" : "actions" } 
    (2) sformat = "{actions} speak louder than {words}"     
    
    result  = "words speak louder than actions"    
    """
    result  = sformat 
    pattern = '\{([^\{\}]+)\}'
    matches = re.findall(pattern, sformat)
    for key in matches:
        key_list = key.split('.')
        value = entry
        keys_exist = True
        for k in key_list:
            if k in value:
                value = value[k]
            else:
                keys_exist = False
                value = None
                break
        if keys_exist == True:
            target = "{" + f"{key}" + "}"
            result = result.replace(target, f"{value}")
    return result