你题目的解答代码如下:(如有帮助,望采纳!谢谢! 点击我这个回答右上方的【采纳】按钮)
data = [
{"year":2000,"month":1,"day":1,"n_birth":800},
{"year":2000,"month":1,"day":2,"n_birth":200},
{"year":2001,"month":1,"day":1,"n_birth":1200},
{"year":2001,"month":1,"day":2,"n_birth":800},
{"year":2001,"month":2,"day":1,"n_birth":1000}
]
month = {}
year = {}
for it in data:
m = month.setdefault(it["month"],{})
m[it["year"]] = m.get(it["year"],0) + it["n_birth"]
year[it["year"]] = year.get(it["year"],0) + it["n_birth"]
print(month)
print(year)
for mk,mv in month.items():
print(f'{mk}月')
for yk,yv in mv.items():
print(f'\t在{yk}年出生人数为{yv}人,占比当年{100/year[yk]*yv:.1f}%')