代码：
[mw_shl_code=python,false]grade_dict = {}
with open("p086_grade.txt", encoding="utf8") as fin:
for line in fin:
sno, grade = line.strip().split(",")
grade_dict[sno] = grade
fout = open("p086.txt", "w", encoding="utf8")
with open("p086_student.txt", encoding="utf8") as f:
for line in f:
sno, sname = line.strip().split(",")
grade = grade_dict[sno]
fout.write(f"{sno},{sname},{grade}\n")
fout.close()[/mw_shl_code]
思路：1.先遍历文件1：file1.txt把每行的两个值以键值的方式存入到字典中