In that case you can directly index the weight matrix:
emb = nn.Embedding(10, 100)
x = torch.tensor([0])
out = emb(x)
out_manual = emb.weight[x, :]
print((out_manual == out).all())
> tensor(True)

I’m not 100% sure, what placeholders in TF are, but aren’t they used to feed data into the graph?