def fen_jie(num): #  递归法
    for i in range(2,num+1):
        if i == num:
            print(i,end="")
            return
        elif num % i == 0:
            print(i,"* ",end="")
            fen_jie(num // i)
            return

def fen_jie2(num):
    while num != 1: # 循环判断法
        for i in range(2,num + 1):
            if num % i == 0:
                print(i,end="")
                num //= i
                if num != 1:
                    print(" * ",end="")
                break

if __name__ == "__main__":
    int_a= 90
    print(int_a," = ",end="")
    fen_jie(int_a)
    print()
    print(int_a," = ",end="")
    fen_jie2(int_a)

输出结果:
90  = 2 * 3 * 3 * 5
90  = 2 * 3 * 3 * 5

您有什么问题吗?

def fen_jie(num): #  递归法
    for i in range(2,num+1):
        if i == num:
            print(i,end="")
            return
        elif num % i == 0:
            print(i,"* ",end="")
            fen_jie(num // i)
            return

def fen_jie2(num):
    while num != 1: # 循环判断法
        for i in range(2,num + 1):
            if num % i == 0:
                print(i,end="")
                num //= i
                if num != 1:
                    print(" * ",end="")
                break

if __name__ == "__main__":
    int_a= 142857
    print(int_a," = ",end="")
    fen_jie(int_a)
    print()
    print(int_a," = ",end="")
    fen_jie2(int_a)

这个程序可以运行，但要分解的数需要再程序中改顶，上面的结果如下：
...
142857  = 3 * 3 * 3 * 11 * 13 * 37
142857  = 3 * 3 * 3 * 11 * 13 * 37>>>

可以改为接收输入:

def fen_jie(num): #  递归法
    for i in range(2,num+1):
        if i == num:
            print(i,end="")
            return
        elif num % i == 0:
            print(i,"* ",end="")
            fen_jie(num // i)
            return

def fen_jie2(num):
    while num != 1: # 循环判断法
        for i in range(2,num + 1):
            if num % i == 0:
                print(i,end="")
                num //= i
                if num != 1:
                    print(" * ",end="")
                break

if __name__ == "__main__":
    while True:
        try:
            int_a= 90
        except:
            print('error')
            break
        print(int_a," = ",end="")
        fen_jie(int_a)
        print()
        print(int_a," = ",end="")
        fen_jie2(int_a)
        

没什么问题,就是我新手,自己写的代码,让大神们给看一下,有没有需要改的地方
谢谢上面几位的指点

[此贴子已经被作者于2023-4-1 22:57编辑过]

def fen_jie(num): #  递归法
    for i in range(2,num+1):
        if i == num:
            print(i,end="")
            return
        elif num % i == 0:
            print(i,"* ",end="")
            fen_jie(num // i)
            return

    def fen_jie2(num):
        while num != 1: # 循环判断法
            for i in range(2,num + 1):
                if num % i == 0:
                    print(i,end="")
                    num //= i
                    if num != 1:
                        print(" * ",end="")
                    break

    if __name__ == "__main__":
        while True:
            try:
                int_a= 90
            except:
                print('error')
                break
            print(int_a," = ",end="")
            fen_jie(int_a)
            print()
            print(int_a," = ",end="")
            fen_jie2(int_a)

这个咋不运行啊？

def fen_jie(num): #  递归法
    for i in range(2,num+1):
        if i == num:
            print(i,end="")
            return
        elif num % i == 0:
            print(i,"* ",end="")
            fen_jie(num // i)
            return

def fen_jie2(num):
    while num != 1: # 循环判断法
        for i in range(2,num + 1):
            if num % i == 0:
                print(i,end="")
                num //= i
                if num != 1:
                    print(" * ",end="")
                break

if __name__ == "__main__":
    while True:
        try:
            int_a= 142857
        except:
            print('error')
            break
        print(int_a," = ",end="")
        fen_jie(int_a)
        print()
        print(int_a," = ",end="")
        fen_jie2(int_a)

def fen_jie(num): #  递归法
    for i in range(2,num+1):
        if i == num:
            print(i,end="")
            return
        elif num % i == 0:
            print(i,"* ",end="")
            fen_jie(num // i)
            return

def fen_jie2(num):
    while num != 1: # 循环判断法
        for i in range(2,num + 1):
            if num % i == 0:
                print(i,end="")
                num //= i
                if num != 1:
                    print(" * ",end="")
                break

if __name__ == "__main__":
    int_a= 142857
    print(int_a," = ",end="")
    fen_jie(int_a)
    print()
    print(int_a," = ",end="")
    fen_jie2(int_a)

def nxyz(fi):  # 整数的因式分解公式，
    xd = list()  # 因子存于此处
    if fi <= 3:
        xd.append(fi)
    if fi >= 4:
        x = 2
        while fi >= x ** 2:
            if fi % x != 0:
                x += 1
            if fi % x == 0:
                xd.append(str(x))
                fi = int(fi / x)
        xd.append(str(fi))
    if len(xd) == 1 and fi != 1:
        ff = "这是质数，不能分解"
        print(ff)
    if fi == 1:
        print("1，不能分解的，嘿嘿！")
    if len(xd) > 1:
        ff = "*".join(xd)
        print(ff)

if __name__ == "__main__":
    fi = eval(input("请输入一个整数：\n"))
    nxyz(fi)