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2024年3月27日发(作者：mysql安装必须安装vc吗)
63 ans = a + b
64 elif operator == '-':
65 ans = a - b
66 elif operator == '*':
67 ans = a * b
68 elif operator == '/':
69 if b == 0:
70 ans = "VALUE ERROR"
71 else:
72 ans = a / b
73 elif operator == '^':
74 if a == 0 and b == 0:
75 ans = "VALUE ERROR"
76 else:
77 ans = a ** b
78
79 return ans
80
81 def calc(exp):
82 """
83 Calculate the ans of exp
84 """
85 exp += '#'
86 operSet = "+-*/^()#"
87 stackOfOperator, stackOfNum = ['#'], []
88 pos, ans, index, length = 0, 0, 0, len(exp)
89 while index < length:
90 e = exp[index]
91 if e in operSet:
92 # calc according to the prior
93 topOperator = ()
94 compare = precede(topOperator, e)
95 if compare == '>':
96 try:
97 b = ()
98 a = ()
99 except:
100 return "FORMAT ERROR"
101 ans = operate(a, b, topOperator)
102 if ans == "VALUE ERROR":
103 return ans
104 else:
105 (ans)
106 elif compare == '<':
107 (topOperator)
108 (e)
109 index += 1
110 elif compare == '=':
111 index += 1
112 elif compare == ' ':
113 return "FORMAT ERROR"
114 else:
115 # get the next num
116 pos = index
117 while not exp[index] in operSet:
118 index += 1
119 temp = exp[pos:index]
120
121 # delete all 0 of float in the end
122 last = index - 1
123 if '.' in temp:
124 while exp[last] == '0':
125 last -= 1
126 temp = exp[pos:last + 1]
127
128 try:
129 temp = Decimal(temp)
130 except:
131 return "INPUT ERROR"
132 (temp)
133
134 if len(stackOfNum) == 1 and stackOfOperator == []:
135 return ()
136 else:
137 return "INPUT ERROR"
138
139 if __name__ == "__main__":
140 # get the exp
141 exp = argv[1]
142
143 # set the precision
144 getcontext().prec = 10
145
146 # delete blanks
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