现在,我想编写一个汇编程序,但我不断收到此错误:使用字典时如何避免KeyError?
Traceback (most recent call last): File "/Users/Douglas/Documents/NeWS.py", line 44, in if item in registerTable[item]: KeyError: 'LD'
我现在有这样的代码:
functionTable = {"ADD":"00",
"SUB":"01",
"LD" :"10"}
registerTable = {"R0":"00",
"R1":"00",
"R2":"00",
"R3":"00"}
accumulatorTable = {"A" :"00",
"B" :"10",
"A+B":"11"}
conditionTable = {"JH":"1"}
valueTable = {"0":"0000",
"1":"0001",
"2":"0010",
"3":"0011",
"4":"0100",
"5":"0101",
"6":"0110",
"7":"0111",
"8":"1000",
"9":"1001",
"10":"1010",
"11":"1011",
"12":"1100",
"13":"1101",
"14":"1110",
"15":"1111"}
source = "LD R3 15"
newS = source.split(" ")
for item in newS:
if item in functionTable[item]:
functionField = functionTable[item]
else:
functionField = "00"
if item in registerTable[item]:
registerField = registerTable[item]
else:
registerField = "00"
print(functionField + registerField)
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莫非你要仔细检查缩进是正确的?我把它格式化为代码,但是如果这是想要的缩进总是很难确定。 :) – MSeifert
就在旁边...你可以在范围(16)中对值为'valueTable = {str(n):format(n,'04b')'' - 这样就可以更容易地改变范围,复制/粘贴错误或以其他方式输入不正确的值和更少的屏幕空间... –