( 32 - 42 / 95 + 24 ( ) ( 53 ) + ) 21
虽然空括号对我来说完全没问题,但我不能在计算中使用这个自动生成的表达式,因为24和53之间没有运算符,并且末尾的+号没有第二个参数。我想知道的是,是否有一种Pythonic的解决方案来解决/修复这些错误?(在任何人指出之前,我首先要承认我所发布的代码可能是我推送过的最糟糕的代码,也基本上不符合Python的核心原则。)
import random
parentheses = ['(',')']
ops = ['+','-','*','/'] + parentheses
lines = 0
while lines < 1000:
fname = open('test.txt','a')
expr = []
numExpr = lines
if (numExpr % 2 == 0):
numExpr += 1
isDiv = False # Boolean var, makes sure there's no Div by 0
# isNumber, isParentheses, isOp determine whether next element is a number, parentheses, or operator, respectively
isNumber = random.randint(0,1) == 0 # determines whether to start sequence with number or parentheses
isParentheses = not isNumber
isOp = False
# Counts parentheses to ensure parentheses are matching
numParentheses = 0
while (numExpr > 0 or numParentheses > 0):
if (numExpr < 0 and numParentheses > 0):
isDiv = False
expr.append(')')
numParentheses -= 1
elif (isOp and numParentheses > 0):
rand = random.randint(0,5)
expr.append(ops[rand])
isDiv = (rand == 3) # True if div op was just appended
# Checks to see if ')' was appended
if (rand == 5):
isNumber = False
isOp = True
numParentheses -= 1
# Checks to see if '(' was appended
elif (rand == 4):
isNumber = True
isOp = False
numParentheses += 1
# All other operations go here
else:
isNumber = True
isOp = False
# Didn't add parentheses possibility here in case expression in parentheses somehow reaches 0
elif (isNumber and isDiv):
expr.append(str(random.randint(1,100)))
isDiv = False
isNumber = False
isOp = True
# If a number's up, decides whether to append parentheses or a number
elif (isNumber):
rand = random.randint(0,1)
if (rand == 0):
expr.append(str(random.randint(0,100)))
isNumber = False
isOp = True
elif (rand == 1):
if (numParentheses == 0):
expr.append('(')
numParentheses += 1
else:
rand = random.randint(0,1)
expr.append(parentheses[rand])
if rand == 0:
numParentheses += 1
else:
numParentheses -= 1
isDiv = False
numExpr -= 1
fname.write(' '.join(expr) + '\n')
fname.close()
lines += 1
__str__
方法。我的意思是,这很有道理,但另一个问题是我正在使用自动生成的表达式来优化程序的运行时间,所以我需要长度计数器。 - Edwin