Python 程序输出数字后跟 'L'

Question

我用 Python 创建了一个程序来生成斐波那契数列或卢卡斯数列中的任意数量的元素(斐波那契数为 1,1,2,3,5,8,13 等，卢卡斯数为 2,1,3,4 ,7,11,18 等)但出于某种原因，每当我针对特定数字(似乎高于某个阈值)运行它时，它都会输出数字后跟大写字母 L。它执行此操作的第一个数字是 2971215073，但其他程序生成的数字远高于没有问题的数字。我如何阻止它这样做？完整代码:

import time
f = [1,1]
l = [2,1]
x = True
while x == True:
    b = raw_input('Would you like to generate fibonacci numbers (enter f) or lucas numbers (enter l)?\n')
    if b == 'l' or b == 'L' or b == 'lucas' or b == 'Lucas':
        z = True
        x = False
    elif b == 'f' or b == 'F' or b == 'fibonnaci' or b == 'Fibonnaci' or b == 'Fibonacci' or b == 'fibonacci':
        z = False
        x = False
    else:
        print 'That isn\'t an answer. Enter f or l.'
y = True
while y == True:
    c = raw_input('Would you like to generate up to a limit (enter a) or a certain number of elements (enter b)?\n')
    if c == 'A' or c == 'a':
        w = True
        y = False
    elif c == 'B' or 'b':
        w = False
        y = False
    else:
        print 'That isn\'t an answer. Enter a or b.'
a = input('Enter an upper bound.\n')
c = 1
if z == True and w == True:
    start = time.clock()
    while((l[c] + l[c-1]) <= a):
        l += [(l[c] + l[c-1])]
        c += 1
    print l
    if (time.clock() - start) >= 60:
        print 'Program took ' + str(time.clock() - start) + ' seconds to run.'
if z == True and w == False:
    start = time.clock()
    while(c-1 <= a-3):
        l += [(l[c] + l[c-1])]
        c += 1
    print l
    if (time.clock() - start) >= 60:
        print 'Program took ' + str(time.clock() - start) + ' seconds to run.'
if z == False and w == True:
    start = time.clock()
    while((f[c] + f[c-1]) <= a):
        f += [(f[c] + f[c-1])]
        c += 1
    print f
    if (time.clock() - start) >= 60:
        print 'Program took ' + str(time.clock() - start) + ' seconds to run.'
if z == False and w == False:
    start = time.clock()
    while(c-1 <= a-3):
        f += [(f[c] + f[c-1])]
        c += 1
    print f
    if (time.clock() - start) >= 60:
        print 'Program took ' + str(time.clock() - start) + ' seoonds to run.'
raw_input('Press enter to exit.')

输出示例:

Would you like to generate fibonacci numbers (enter f) or lucas numbers (enter l)?
f
Would you like to generate up to a limit (enter a) or a certain number of elements (enter b)?
b
Enter an upper bound.
100



  [1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597,
 2584, 4181, 6765, 10946, 17711, 28657, 46368, 75025, 121393, 196418, 317811,
     514229, 832040, 1346269, 2178309, 3524578, 5702887, 9227465, 14930352,
     24157817, 39088169, 63245986, 102334155, 165580141, 267914296, 433494437, 701408733, 1134903170, 1836311903, 2971215073L, 4807526976L, 7778742049L,
     12586269025L, 20365011074L, 32951280099L, 53316291173L, 86267571272L,
     139583862445L, 225851433717L, 365435296162L, 591286729879L, 956722026041L, 1548008755920L, 2504730781961L, 4052739537881L, 6557470319842L, 
    10610209857723L, 17167680177565L, 27777890035288L, 44945570212853L, 
    72723460248141L, 117669030460994L, 190392490709135L, 308061521170129L, 
    498454011879264L, 806515533049393L, 1304969544928657L, 2111485077978050L,
     3416454622906707L, 5527939700884757L, 8944394323791464L, 14472334024676221L,
     23416728348467685L, 37889062373143906L, 61305790721611591L, 
    99194853094755497L, 160500643816367088L, 259695496911122585L, 420196140727489673L, 679891637638612258L, 1100087778366101931L, 1779979416004714189L, 2880067194370816120L, 4660046610375530309L,
     7540113804746346429L, 12200160415121876738L, 19740274219868223167L,
     31940434634990099905L, 51680708854858323072L, 83621143489848422977L,
     135301852344706746049L, 218922995834555169026L, 354224848179261915075L]
        Press enter to exit.

Answer 1

L 是 Python 2 的一个怪癖，表示“长整数”。如果您单独打印数字(而不是打印列表)，则不会有“L”。另一种选择是升级到 Python 3，这消除了这个怪癖。

考虑更换:

print l

与

print ", ".join(str(x) for x in l)

如果你还想要方括号，那么你可以使用格式化:

print "[{}]".format(", ".join(str(x) for x in l))