def read_from(self, data, pad=<NUM_LIT:0>):
for i in range(self.BEGIN, self.END + <NUM_LIT:1>):<EOL><INDENT>index = self.index(i, len(data))<EOL>yield pad if index is None else data[index]<EOL><DEDENT>
Returns a generator with the elements "data" taken by offset, restricted
by self.begin and self.end, and padded on either end by `pad` to get
back to the original length of `data`