逻辑门是任何数字电路的基本构建块。它需要一两个输入并根据这些输入产生输出。输出可能为高 (1) 或低 (0)。逻辑门使用二极管或晶体管实现。它也可以使用真空管、光学元件、分子等电磁元件构成。在计算机中，大多数电子电路都是由逻辑门组成的。逻辑门用于执行计算、数据存储或展示面向对象编程（尤其是继承的力量）的电路。
定义了七个基本逻辑门：与门、或门、非门、与非门、或非门、异或门、异或门。
1. 与门
如果两个输入都为 1，与门的输出为 1，否则为 0。
# 说明与门工作的 Python3 程序 def AND (a, b): if a == 1 and b == 1: return True else: return False # 驱动程序代码 if __name__=='__main__': print(AND(1, 1)) print("+---------------+----------------+") print(" | AND Truth Table | Result |") print(" A = False, B = False | A AND B =",AND(False,False)," | ") print(" A = False, B = True | A AND B =",AND(False,True)," | ") print(" A = True, B = False | A AND B =",AND(True,False)," | ") print(" A = True, B = True | A AND B =",AND(True,True)," | ")
输出：
True +---------------+---------------- | AND Truth Table | Result | A = False, B = False | A AND B = False | A = False, B = True | A AND B = False | A = True, B = False | A AND B = False | A = True, B = True | A AND B = True |
2. 与非门
如果两个输入都是 1，与非门（取反）输出 0，否则输出 1。
# 说明与非门工作的Python3程序 def NAND (a, b): if a == 1 and b == 1: return False else: return True # 驱动程序代码 if __name__=='__main__': print(NAND(1, 0)) print("+---------------+----------------+") print(" | NAND Truth Table | Result |") print(" A = False, B = False | A AND B =",NAND(False,False)," | ") print(" A = False, B = True | A AND B =",NAND(False,True)," | ") print(" A = True, B = False | A AND B =",NAND(True,False)," | ") print(" A = True, B = True | A AND B =",NAND(True,True)," | ")
输出：
True +---------------+---------------- | NAND Truth Table | Result | A = False, B = False | A AND B = True | A = False, B = True | A AND B = True | A = True, B = False | A AND B = True | A = True, B = True | A AND B = False |
3. 或门
如果两个输入中的任何一个为 1，或门的输出为 1，否则为 0。
# Python3 程序来说明或门的工作 def OR(a, b): if a == 1 or b ==1: return True else: return False # 驱动程序代码 if __name__=='__main__': print(OR(0, 0)) print("+---------------+----------------+") print(" | OR Truth Table | Result |") print(" A = False, B = False | A OR B =",OR(False,False)," | ") print(" A = False, B = True | A OR B =",OR(False,True)," | ") print(" A = True, B = False | A OR B =",OR(True,False)," | ") print(" A = True, B = True | A OR B =",OR(True,True)," | ")
输出：
False +---------------+----------------+ | OR Truth Table | Result | A = False, B = False | A OR B = False | A = False, B = True | A OR B = True | A = True, B = False | A OR B = True | A = True, B = True | A OR B = True |
4. 异或
门 如果输入中的任何一个不同，异或门的输出为 1，如果它们相同，则输出为 0。
# 说明异或门工作的 Python3 程序 def XOR (a, b): if a != b: return 1 else: return 0 # 驱动程序代码 if __name__=='__main__': print(XOR(5, 5)) print("+---------------+----------------+") print(" | XOR Truth Table | Result |") print(" A = False, B = False | A XOR B =",XOR(False,False)," | ") print(" A = False, B = True | A XOR B =",XOR(False,True)," | ") print(" A = True, B = False | A XOR B =",XOR(True,False)," | ") print(" A = True, B = True | A XOR B =",XOR(True,True)," | ")
输出：
0 +---------------+----------------+ | XOR Truth Table | Result | A = False, B = False | A XOR B = 0 | A = False, B = True | A XOR B = 1 | A = True, B = False | A XOR B = 1 | A = True, B = True | A XOR B = 0 |
5. NOT Gate
它作为一个反相器。它只需要一个输入。如果输入为 1，它会将结果反转为 0，反之亦然。
# Python3 程序来说明非门的工作原理 def NOT(a): return not a # 驱动程序代码 if __name__=='__main__': print(NOT(0)) print("+---------------+----------------+") print(" | NOT Truth Table | Result |") print(" A = False | A NOT =",NOT(False)," | ") print(" A = True, | A NOT =",NOT(True)," | ")
输出：
1 +---------------+----------------+ | NOT Truth Table | Result | A = False | A NOT = 1 | A = True, | A NOT = 0 |
6. NOR 门
NOR 门（取反的 OR）如果两个输入都为 0，则输出为 1，否则为 0。
# Python3程序来说明或非门的工作 def NOR(a, b): if(a == 0) and (b == 0): return 1 elif(a == 0) and (b == 1): return 0 elif(a == 1) and (b == 0): return 0 elif(a == 1) and (b == 1): return 0 # 驱动程序代码 if __name__=='__main__': print(NOR(0, 0)) print("+---------------+----------------+") print(" | NOR Truth Table | Result |") print(" A = False, B = False | A NOR B =",NOR(False,False)," | ") print(" A = False, B = True | A NOR B =",NOR(False,True)," | ") print(" A = True, B = False | A NOR B =",NOR(True,False)," | ") print(" A = True, B = True | A NOR B =",NOR(True,True)," | ")
输出：
1 +---------------+----------------+ | NOR Truth Table | Result | A = False, B = False | A NOR B = 1 | A = False, B = True | A NOR B = 0 | A = True, B = False | A NOR B = 0 | A = True, B = True | A NOR B = 0 |
7. XNOR 门
XNOR 门（取反的 XOR）输出 1，两个输入相同，如果两者不同，则输出 0。
# Python3 程序来说明非门的工作原理 def XNOR(a,b): if(a == b): return 1 else: return 0 # 驱动程序代码 if __name__=='__main__': print(XNOR(1,1)) print("+---------------+----------------+") print(" | XNOR Truth Table | Result |") print(" A = False, B = False | A XNOR B =",XNOR(False,False)," | ") print(" A = False, B = True | A XNOR B =",XNOR(False,True)," | ") print(" A = True, B = False | A XNOR B =",XNOR(True,False)," | ") print(" A = True, B = True | A XNOR B =",XNOR(True,True)," | ")
输出：
1 +---------------+----------------+ | XNOR Truth Table | Result | A = False, B = False | A XNOR B = 1 | A = False, B = True | A XNOR B = 0 | A = True, B = False | A XNOR B = 0 | A = True, B = True | A XNOR B = 1 |
