<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def placeholders(cls,dic):
 """Placeholders for fields names and value binds"""

        keys = [str(x) for x in dic]
        entete = ",".join(keys)
        placeholders = ",".join(cls.named_style.format(x) for x in keys)
        entete = f"({entete})"
        placeholders = f"({placeholders})"
        return entete, placeholders