  Measurements of $CP$ observables in $B^\pm \rightarrow D^{(*)} K^\pm$ and
$B^\pm \rightarrow D^{(*)} \pi^\pm$ decays are presented, where $D^{(*)}$
indicates a neutral $D$ or $D^*$ meson that is an admixture of $D^{(*)0}$ and
$\bar{D}^{(*)0}$ states. Decays of the $D^*$ meson to the $D\pi^0$ and
$D\gamma$ final states are partially reconstructed without inclusion of the
neutral pion or photon, resulting in distinctive shapes in the $B$ candidate
invariant mass distribution. Decays of the $D$ meson are fully reconstructed in
the $K^\pm \pi^\mp$, $K^+ K^-$ and $\pi^+ \pi^-$ final states. The analysis
uses a sample of charged $B$ mesons produced in $pp$ collisions collected by
the LHCb experiment, corresponding to an integrated luminosity of 2.0, 1.0 and
2.0 fb$^{-1}$ taken at centre-of-mass energies of $\sqrt{s}$ = 7, 8 and 13 TeV,
respectively. The study of $B^{\pm} \to D^{*} K^{\pm}$ and $B^{\pm} \to D^{*}
\pi^{\pm}$ decays using a partial reconstruction method is the first of its
kind, while the measurement of $B^{\pm} \to D K^{\pm}$ and $B^{\pm} \to D
\pi^{\pm}$ decays is an update of previous LHCb measurements. The $B^{\pm} \to
D K^{\pm}$ results are the most precise to date.
