Python制作化学术语查询工具 修复查询时输出全部定义的问题

问题原因 #

• 未存储用户输入：input("What would you like to know?\n")的返回值没有赋值给变量，用户输入的查询内容直接被丢弃，没有参与后续判断。
• 判断逻辑错误：Python中非空字符串的布尔值恒为True，你写的if "VolumeUnits":这类判断等价于直接写if True:，所有分支都会触发，因此会打印全部定义。

优化后实现方案 #

推荐用字典存储术语和对应释义，后续增删术语只需要修改字典内容即可，不需要添加大量if判断，维护成本更低，完整代码如下：

# 用字典存储术语-释义映射，后续新增词条直接在这里添加即可
glossary = {
    "Imperial": "英制单位，包含gal、cup、汤匙、茶匙、夸脱、盎司、品脱等容积单位", # 你原代码缺失Imperial的定义，可根据需求修改释义
    "VolumeUnits": "gal, cup, table spoons, teaspoons, quart, ounces, pints",
    "MetricSystem": "基于米作为基准，采用10的幂次进位的单位体系",
    "PreFixes": """kilo 
hecto 
deka 
base 
deci 
centi 
mili""",
    "Mass": "物体所含物质的量，基本单位是千克",
    "Weight": "重力对质量的作用力",
    "Volume": "长度×宽度×高度",
    "Random": "1升 = 1立方分米，1毫升 = 1立方厘米",
    "Time": "基本单位是秒",
    "Temperature": "常用单位摄氏度、开尔文",
    "SigFig": "可以置信测量的最后一位数值",
    "Chemistry": "研究物质及其性质、反应的学科",
    "Matter": "任何占有空间且具有质量的事物"
}

# 获取并存储用户输入
query = input("你想查询哪个术语的定义？\n")

# 判断查询内容是否在词表中，存在则打印释义，不存在则提示
if query in glossary:
    print(glossary[query])
else:
    print("你查询的术语暂未收录")

如果你一定要沿用原有的变量+if判断的写法，修改方式如下：

# 保留你原来的变量定义
VolumeUnits = "gal, cup, table spoons, teaspoons, quart, ounces, pints"
MetricSystem = "Based on the meter, really just a stick, Based on powers of 10"
PreFixes = """kilo 
hecto 
deka 
base 
deci 
centi 
mili"""
Mass = "the amount of matter in an object, base unit is kilograms"
Weight = "the pull of gravity on a mass"
Volume = "lenght x width x height"
Random = "1L - dm^3.  1ml - cm^3"
Time = "base is seconds"
Temperature = "Celsius, kelvin"
SigFig = "the last number that can be measured with confidence"
Chemistry = "the study of matter and its properties and reactions"
Matter = "anything that takes up space and has mass"
Imperial = "英制单位的定义内容" # 你原代码缺失了Imperial变量的定义，需要先补全

# 存储用户输入
query = input("What would you like to know?\n")

# 把判断改成匹配用户输入的内容，用elif避免无效判断
if query == "Imperial":
    print(Imperial)
elif query == "VolumeUnits":
     print(VolumeUnits)
elif query == "MetricSystem":
     print(MetricSystem)
elif query == "PreFixes":
     print(PreFixes)
elif query == "Mass":
     print(Mass)
elif query == "Weight":
     print(Weight)
elif query == "Volume":
     print(Volume)
elif query == "Random":
     print(Random)
elif query == "Time":
     print(Time)
elif query == "Temperature":
     print(Temperature)
elif query == "SigFig":
     print(SigFig)
elif query == "Chemistry":
     print(Chemistry)
elif query == "Matter":
     print(Matter)
else:
    print("未查询到对应术语")

内容的提问来源于stack exchange，提问作者PetaByte