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。
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 |
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 |
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 |
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 |
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 |
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
+---------------+----------------+
| NOT Truth Table | Result |
A = False | A NOT = 1 |
A = True, | A NOT = 0 |
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 |
