Does add_format function work with multisample vcf file ?

[giacuong171]

I'm using vcfpy to add an extra field in FORMAT of each record of a multisamples vcf file. From the document, i think that the function add_format would help me to do that. However, it keeps adding the same values for every sample. How can i add different value for each sample?

[giacuong171]

def add_format(self, key, value=None):
        """Add an entry to format

        The record's calls ``data[key]`` will be set to ``value`` if not yet
        set and value is not ``None``.  If key is already in FORMAT then
        nothing is done.
        """
        if key in self.FORMAT:
            return
        self.FORMAT.append(key)
        if value is not None:
            for call in self:
                call.data.setdefault(key, value)

What I understand is that, in this code line "call.data.setdefault(key,value)", key here should be the new field in the Format,and value should be the value for that new field. If so, then it will add the same value for all samples ?