参考博客
代码实现模拟进程（码云）
def InitializationError(param):
pass
class Statestart:
def __init__(self):
self.handlers = {} # 状态转移函数字典
self.startState = None # 初始状态
self.endStates = [] # 最终状态集合
# 参数name为状态名,handler为状态转移函数,end_state表明是否为最终状态
def add_state(self, name, handler, end_state=0):
name = name.upper() # 转换为大写
self.handlers[name] = handler
if end_state:
self.endStates.append(name)
def set_start(self, name):
self.startState = name.upper()
def run(self, appgo):
try:
handler = self.handlers[self.startState]
except:
raise InitializationError("must call .set_start() before .run()")
if not self.endStates:
raise InitializationError("at least one state must be an end_state")
# 从Start状态开始进行处理
while True:
(newState, appgo) = handler(appgo) # 经过状态转移函数变换到新状态
if newState.upper() in self.endStates: # 如果跳到终止状态,则打印状态并结束循环
print("reached ", newState)
break
else: # 否则将转移函数切换为新状态下的转移函数
handler = self.handlers[newState.upper()]
# 有限状态集合
positive_adjectives = ["new", "ready", "running", "waiting", "terminated"]
negative_adjectives = ["unnew", "unready", "unrunning", "unwaiting", "unterminated"]
# 自定义状态转变函数
def start_transitions(txt):
splitted_txt = txt.split(None, 1)
word, txt = splitted_txt if len(splitted_txt) > 1 else (txt, "")
if word == "Python":
newState = "Python_state" # 如果第一个词是Python则可转换到"Python状态"
else:
newState = "error_state" # 如果第一个词不是Python则进入终止状态
return (newState, txt) # 返回新状态和余下的语句txt
def python_state_transitions(txt):
splitted_txt = txt.split(None, 1)
word, txt = splitted_txt if len(splitted_txt) > 1 else (txt, "")
if word == "is":
newState = "is_state"
else:
newState = "error_state"
return (newState, txt)
def is_state_transitions(txt):
splitted_txt = txt.split(None, 1)
word, txt = splitted_txt if len(splitted_txt) > 1 else (txt, "")
if word == "not":
newState = "not_state"
elif word in positive_adjectives and word == "new":
newState = "pos_state"
elif word in positive_adjectives and word == "ready":
newState = "pos_state"
elif word in positive_adjectives and word == "running":
newState = "pos_state"
elif word in positive_adjectives and word == "waiting":
newState = "pos_state"
elif word in positive_adjectives and word == "terminated":
newState = "pos_state"
elif word in negative_adjectives and word == "unnew":
newState = "neg_state"
elif word in negative_adjectives and word == "unready":
newState = "neg_state"
elif word in negative_adjectives and word == "unrunning":
newState = "neg_state"
elif word in negative_adjectives and word == "unwaiting":
newState = "neg_state"
elif word in negative_adjectives and word == "unterminated":
newState = "neg_state"
else:
newState = "error_state"
if word == "not":
pass
elif newState == "error_state":
print('程序状态错误')
else:
print("程序状态转换至",word)
return (newState, txt)
def not_state_transitions(txt):
splitted_txt = txt.split(None, 1)
word, txt = splitted_txt if len(splitted_txt) > 1 else (txt, "")
if word in positive_adjectives and word == "new":
newState = "neg_state"
elif word in positive_adjectives and word == "ready":
newState = "neg_state"
elif word in positive_adjectives and word == "running":
newState = "neg_state"
elif word in positive_adjectives and word == "waiting":
newState = "neg_state"
elif word in positive_adjectives and word == "terminated":
newState = "neg_state"
elif word in negative_adjectives and word == "unnew":
newState = "pos_state"
elif word in negative_adjectives and word == "unready":
newState = "pos_state"
elif word in negative_adjectives and word == "unrunning":
newState = "pos_state"
elif word in negative_adjectives and word == "unwaiting":
newState = "pos_state"
elif word in negative_adjectives and word == "unterminated":
newState = "pos_state"
else:
newState = "error_state"
if word in negative_adjectives:
print("程序状态转换至",word)
elif newState == "error_state":
print('程序状态错误')
else:
print("程序状态转换至 not",word)
return (newState, txt)
if __name__ == "__main__":
m = Statestart()
m.add_state("Start", start_transitions) # 添加初始状态
m.add_state("Python_state", python_state_transitions)
m.add_state("is_state", is_state_transitions)
m.add_state("not_state", not_state_transitions)
m.add_state("neg_state", None, end_state=1) # 添加最终状态
m.add_state("pos_state", None, end_state=1)
m.add_state("error_state", None, end_state=1)
option = input("请输入是否执行程序（Yes执行/输入其他内容终止程序）：")
while option == "Yes":
m.set_start("Start") # 设置开始状态
state = input("请输入程序状态（new, ready, running, waiting, terminated或加前缀un）(例如:Python is xxx或Python is not xxx):")
m.run(state)
option = input("请输入是否执行程序（Yes执行/输入其他内容终止程序）：")
else:
print("程序终止")
运行效果
