如何格式化Python条件语句输出为规整表格并适配长姓名

问题背景 #

需要为联合授课班级计算成绩并输出规整的表格格式，现有Python代码可正常运行但格式不符合要求，调整格式化代码后，仍存在长姓名会挤乱成绩列位置的问题。

原始代码 #

n,s,p = input("Input your Name, section, and points separated by a comma").split(",")
st= float(s)
po= float(p)
if st == 435:
    grade = (po/600)*100
    if grade < 60:
        print("SECTION", "STUDENT", "GRADE")
        print("GSP", s, "F")
    elif grade >= 60:
        print("SECTION", "STUDENT", "GRADE")
        print("GSP", s, "D")
    elif grade >= 70:
        print("SECTION", "STUDENT", "GRADE")
        print("GSP", s, "C")
    elif grade >= 80:
        print("SECTION", "STUDENT", "GRADE")
        print("GSP", s, "B")
    elif grade >= 90:
        print("SECTION", "STUDENT", "GRADE")
        print("GSP", s, "A")
elif st == 535:
    grade = (po/700)*100
    if grade < 60:
        print("SECTION", "STUDENT", "GRADE")
        print("GSP", s, "F")
    elif grade >= 60:
        print("SECTION", "STUDENT", "GRADE")
        print("GSP", s, "D")
    elif grade >= 70:
        print("SECTION", "STUDENT", "GRADE")
        print("GSP", s, "C")
    elif grade >= 80:
        print("SECTION", "STUDENT", "GRADE")
        print("GSP", s, "B")
    elif grade >= 90:
        print("SECTION", "STUDENT", "GRADE")
        print("GSP", s, "A") 

修改后仍有问题的代码 #

n,s,p = input("Input your Name, section, and points separated by a comma").split(",")

st= float(s)
po= float(p)
if st == 435:
    grade = (po/600)*100
    if grade < 60:
        print("SECTION", "STUDENT", "GRADE")
        print('{:7s} {:7s} {:5s}'.format("GSP "+s,n, "F"))
    elif 60 <= grade < 70:
        print("SECTION", "STUDENT", "GRADE")
        print('{:7s} {:7s} {:5s}'.format("GSP "+s,n, "D"))
    elif 70 <= grade < 80:
        print("SECTION", "STUDENT", "GRADE")
        print('{:7s} {:7s} {:5s}'.format("GSP "+s,n, "C"))
    elif 80 <= grade < 90:
        print("SECTION", "STUDENT", "GRADE")
        print('{:7s} {:7s} {:5s}'.format("GSP "+s,n, "B"))
    elif 90 <= grade < 100:
        print("SECTION", "STUDENT", "GRADE")
        print('{:7s} {:7s} {:5s}'.format("GSP "+s,n, "A"))

elif st == 535:
    grade = (po/700) * 100
    if grade < 60:
        print("SECTION", "STUDENT", "GRADE")
        print('{:7s} {:7s} {:5s}'.format("GSP "+ s, n, "F"))
    elif 60 <= grade < 70:
        print("SECTION", "STUDENT", "GRADE")
        print('{:7s} {:7s} {:5s}'.format("GSP "+ s, n, "D"))
    elif 70 <= grade < 80:
        print("SECTION", "STUDENT", "GRADE")
        print('{:7s} {:7s} {:5s}'.format("GSP "+ s, n, "C"))
    elif 80 <= grade < 90:
        print("SECTION", "STUDENT", "GRADE")
        print('{:7s} {:7s} {:5s}'.format("GSP "+ s, n, "B"))
    elif 90 <= grade < 100:
        print("SECTION", "STUDENT", "GRADE")
        print('{:7s} {:7s} {:5s}'.format("GSP "+ s, n, "A"))

问题原因 #

修改后的代码使用固定宽度格式化字符串（如{:7s}），当姓名长度超过设定的7个字符时，会突破宽度限制，导致后续列错位。同时原代码等级判断逻辑存在覆盖问题（如elif grade >=60会跳过70/80/90的判断）。

解决方案 #

方案1：动态计算列宽度（无依赖） #

根据输入姓名和表头的长度动态调整列宽，确保所有内容对齐：

n,s,p = input("输入姓名、班级、分数，用逗号分隔").split(",")
st = float(s)
po = float(p)

# 计算百分比成绩
if st == 435:
    grade_percent = (po / 600) * 100
elif st == 535:
    grade_percent = (po / 700) * 100
else:
    print("无效班级")
    exit()

# 确定等级字母（修复原逻辑覆盖问题）
if grade_percent < 60:
    grade_letter = "F"
elif 60 <= grade_percent <70:
    grade_letter = "D"
elif 70 <= grade_percent <80:
    grade_letter = "C"
elif 80 <= grade_percent <90:
    grade_letter = "B"
else:
    grade_letter = "A"

# 动态计算列宽：取内容和表头的最大长度+2留余量
section_col_width = max(len(f"GSP {s}"), len("SECTION")) + 2
name_col_width = max(len(n), len("STUDENT")) + 2
grade_col_width = max(len(grade_letter), len("GRADE")) + 2

# 格式化输出表头和内容
header = f"{{:<{section_col_width}}}{{:<{name_col_width}}}{{:<{grade_col_width}}}".format("SECTION", "STUDENT", "GRADE")
content = f"{{:<{section_col_width}}}{{:<{name_col_width}}}{{:<{grade_col_width}}}".format(f"GSP {s}", n, grade_letter)

print(header)
print(content)

方案2：使用tabulate库（简洁高效） #

借助第三方库自动适配列宽，输出规整表格：

1. 安装库：pip install tabulate
2. 代码实现：

from tabulate import tabulate

n,s,p = input("输入姓名、班级、分数，用逗号分隔").split(",")
st = float(s)
po = float(p)

# 计算百分比成绩
if st == 435:
    grade_percent = (po / 600) * 100
elif st == 535:
    grade_percent = (po / 700) * 100
else:
    print("无效班级")
    exit()

# 确定等级字母
if grade_percent < 60:
    grade_letter = "F"
elif 60 <= grade_percent <70:
    grade_letter = "D"
elif 70 <= grade_percent <80:
    grade_letter = "C"
elif 80 <= grade_percent <90:
    grade_letter = "B"
else:
    grade_letter = "A"

# 用tabulate输出规整表格
table_data = [
    ["SECTION", "STUDENT", "GRADE"],
    [f"GSP {s}", n, grade_letter]
]
print(tabulate(table_data, headers="firstrow", tablefmt="plain"))

内容的提问来源于stack exchange，提问作者PieCharmer