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 $Dpi^0$ and $Dgamma$ 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.
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