pitchtools.iterate_named_chromatic_pitch_pairs_forward_in_expr

abjad.tools.pitchtools.iterate_named_chromatic_pitch_pairs_forward_in_expr.iterate_named_chromatic_pitch_pairs_forward_in_expr(expr)[source]

New in version 2.0.

Iterate left-to-right, top-to-bottom named chromatic pitch pairs in expr:

abjad> score = Score([])
abjad> notes = [Note("c'8"), Note("d'8"), Note("e'8"), Note("f'8"), Note("g'4")]
abjad> score.append(Staff(notes))
abjad> notes = [Note(x, (1, 4)) for x in [-12, -15, -17]]
abjad> score.append(Staff(notes))
abjad> contexttools.ClefMark('bass')(score[1])
ClefMark('bass')(Staff{3})
abjad> f(score)
\new Score <<
    \new Staff {
        c'8
        d'8
        e'8
        f'8
        g'4
    }
    \new Staff {
        \clef "bass"
        c4
        a,4
        g,4
    }
>>
abjad> for pair in pitchtools.iterate_named_chromatic_pitch_pairs_forward_in_expr(score):
...     pair
...
(NamedChromaticPitch("c'"), NamedChromaticPitch('c'))
(NamedChromaticPitch("c'"), NamedChromaticPitch("d'"))
(NamedChromaticPitch('c'), NamedChromaticPitch("d'"))
(NamedChromaticPitch("d'"), NamedChromaticPitch("e'"))
(NamedChromaticPitch("d'"), NamedChromaticPitch('a,'))
(NamedChromaticPitch('c'), NamedChromaticPitch("e'"))
(NamedChromaticPitch('c'), NamedChromaticPitch('a,'))
(NamedChromaticPitch("e'"), NamedChromaticPitch('a,'))
(NamedChromaticPitch("e'"), NamedChromaticPitch("f'"))
(NamedChromaticPitch('a,'), NamedChromaticPitch("f'"))
(NamedChromaticPitch("f'"), NamedChromaticPitch("g'"))
(NamedChromaticPitch("f'"), NamedChromaticPitch('g,'))
(NamedChromaticPitch('a,'), NamedChromaticPitch("g'"))
(NamedChromaticPitch('a,'), NamedChromaticPitch('g,'))
(NamedChromaticPitch("g'"), NamedChromaticPitch('g,'))

Chords are handled correctly.

abjad> chord_1 = Chord([0, 2, 4], (1, 4))
abjad> chord_2 = Chord([17, 19], (1, 4))
abjad> staff = Staff([chord_1, chord_2])
abjad> f(staff)
\new Staff {
    <c' d' e'>4
    <f'' g''>4
}
abjad> for pair in pitchtools.iterate_named_chromatic_pitch_pairs_forward_in_expr(staff):
...   print pair
(NamedChromaticPitch("c'"), NamedChromaticPitch("d'"))
(NamedChromaticPitch("c'"), NamedChromaticPitch("e'"))
(NamedChromaticPitch("d'"), NamedChromaticPitch("e'"))
(NamedChromaticPitch("c'"), NamedChromaticPitch("f''"))
(NamedChromaticPitch("c'"), NamedChromaticPitch("g''"))
(NamedChromaticPitch("d'"), NamedChromaticPitch("f''"))
(NamedChromaticPitch("d'"), NamedChromaticPitch("g''"))
(NamedChromaticPitch("e'"), NamedChromaticPitch("f''"))
(NamedChromaticPitch("e'"), NamedChromaticPitch("g''"))
(NamedChromaticPitch("f''"), NamedChromaticPitch("g''"))

Return generator.

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