with open('input.po', 'r') as input:
    lines = input.readlines()

for line in lines:
    prev = lines[lines.index(line) - 1]
    if line.startswith('msgstr ') and prev.startswith('msgid '):
        if line.lstrip('msgstr ') == prev.lstrip('msgid '):
            lines[lines.index(line)] = 'msgstr ""'

with open('output.po', 'w') as output:
    for line in lines:
        output.write(line)