下面提供的 Python 代码将 Python 整数转换为任意基数(从 2 到无穷大)的字符串,并且可以双向工作。因此,所有创建的字符串都可以通过为 N 提供字符串而不是整数来转换回 Python 整数。该代码仅适用于有意的正数(在我看来,我不想深入研究负值及其位表示的一些麻烦)。只需从此代码中选择您需要、想要或喜欢的内容,或者只是愉快地了解可用选项。很多只是为了记录所有各种可用的方法(例如,Oneliner 似乎并不快,即使承诺会如此)。
我喜欢 Salvador Dali 提出的无限大基地的格式。一个很好的提议,即使对于简单的二进制位表示也能很好地工作。请注意,对于infiniteBase=True 格式的字符串,width=x 填充参数适用于数字而不是整数。看起来,处理infiniteBase 数字格式的代码比其他选项运行得更快——另一个使用它的原因是什么?
我不喜欢使用 Unicode 来扩展可用于数字的符号数量,所以不要查看下面的代码,因为它不存在。改用建议的infiniteBase 格式或将整数存储为字节以用于压缩目的。
def inumToStr( N, base=2, width=1, infiniteBase=False,\
useNumpy=False, useRecursion=False, useOneliner=False, \
useGmpy=False, verbose=True):
''' Positive numbers only, but works in BOTH directions.
For strings in infiniteBase notation set for bases <= 62
infiniteBase=True . Examples of use:
inumToStr( 17, 2, 1, 1) # [1,0,0,0,1]
inumToStr( 17, 3, 5) # 00122
inumToStr(245, 16, 4) # 00F5
inumToStr(245, 36, 4,0,1) # 006T
inumToStr(245245245245,36,10,0,1) # 0034NWOQBH
inumToStr(245245245245,62) # 4JhA3Th
245245245245 == int(gmpy2.mpz('4JhA3Th',62))
inumToStr(245245245245,99,2) # [25,78, 5,23,70,44]
----------------------------------------------------
inumToStr( '[1,0,0,0,1]',2, infiniteBase=True ) # 17
inumToStr( '[25,78, 5,23,70,44]', 99) # 245245245245
inumToStr( '0034NWOQBH', 36 ) # 245245245245
inumToStr( '4JhA3Th' , 62 ) # 245245245245
----------------------------------------------------
--- Timings for N = 2**4096, base=36:
standard: 0.0023
infinite: 0.0017
numpy : 0.1277
recursio; 0.0022
oneliner: 0.0146
For N = 2**8192:
standard: 0.0075
infinite: 0.0053
numpy : 0.1369
max. recursion depth exceeded: recursio/oneliner
'''
show = print
if type(N) is str and ( infiniteBase is True or base > 62 ):
lstN = eval(N)
if verbose: show(' converting a non-standard infiniteBase bits string to Python integer')
return sum( [ item*base**pow for pow, item in enumerate(lstN[::-1]) ] )
if type(N) is str and base <= 36:
if verbose: show('base <= 36. Returning Python int(N, base)')
return int(N, base)
if type(N) is str and base <= 62:
if useGmpy:
if verbose: show(' base <= 62, useGmpy=True, returning int(gmpy2.mpz(N,base))')
return int(gmpy2.mpz(N,base))
else:
if verbose: show(' base <= 62, useGmpy=False, self-calculating return value)')
lstStrOfDigits="0123456789"+ \
"abcdefghijklmnopqrstuvwxyz".upper() + \
"abcdefghijklmnopqrstuvwxyz"
dictCharToPow = {}
for index, char in enumerate(lstStrOfDigits):
dictCharToPow.update({char : index})
return sum( dictCharToPow[item]*base**pow for pow, item in enumerate(N[::-1]) )
#:if
#:if
if useOneliner and base <= 36:
if verbose: show(' base <= 36, useOneliner=True, running the Oneliner code')
d="0123456789abcdefghijklmnopqrstuvwxyz"
baseit = lambda a=N, b=base: (not a) and d[0] or \
baseit(a-a%b,b*base)+d[a%b%(base-1) or (a%b) and (base-1)]
return baseit().rjust(width, d[0])[1:]
if useRecursion and base <= 36:
if verbose: show(' base <= 36, useRecursion=True, running recursion algorythm')
BS="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
def to_base(n, b):
return "0" if not n else to_base(n//b, b).lstrip("0") + BS[n%b]
return to_base(N, base).rjust(width,BS[0])
if base > 62 or infiniteBase:
if verbose: show(' base > 62 or infiniteBase=True, returning a non-standard digits string')
# Allows arbitrary large base with 'width=...'
# applied to each digit (useful also for bits )
N, digit = divmod(N, base)
strN = str(digit).rjust(width, ' ')+']'
while N:
N, digit = divmod(N, base)
strN = str(digit).rjust(width, ' ') + ',' + strN
return '[' + strN
#:if
if base == 2:
if verbose: show(" base = 2, returning Python str(f'{N:0{width}b}')")
return str(f'{N:0{width}b}')
if base == 8:
if verbose: show(" base = 8, returning Python str(f'{N:0{width}o}')")
return str(f'{N:0{width}o}')
if base == 16:
if verbose: show(" base = 16, returning Python str(f'{N:0{width}X}')")
return str(f'{N:0{width}X}')
if base <= 36:
if useNumpy:
if verbose: show(" base <= 36, useNumpy=True, returning np.base_repr(N, base)")
import numpy as np
strN = np.base_repr(N, base)
return strN.rjust(width, '0')
else:
if verbose: show(' base <= 36, useNumpy=False, self-calculating return value)')
lstStrOfDigits="0123456789"+"abcdefghijklmnopqrstuvwxyz".upper()
strN = lstStrOfDigits[N % base] # rightmost digit
while N >= base:
N //= base # consume already converted digit
strN = lstStrOfDigits[N % base] + strN # add digits to the left
#:while
return strN.rjust(width, lstStrOfDigits[0])
#:if
#:if
if base <= 62:
if useGmpy:
if verbose: show(" base <= 62, useGmpy=True, returning gmpy2.digits(N, base)")
import gmpy2
strN = gmpy2.digits(N, base)
return strN.rjust(width, '0')
# back to Python int from gmpy2.mpz with
# int(gmpy2.mpz('4JhA3Th',62))
else:
if verbose: show(' base <= 62, useGmpy=False, self-calculating return value)')
lstStrOfDigits= "0123456789" + \
"abcdefghijklmnopqrstuvwxyz".upper() + \
"abcdefghijklmnopqrstuvwxyz"
strN = lstStrOfDigits[N % base] # rightmost digit
while N >= base:
N //= base # consume already converted digit
strN = lstStrOfDigits[N % base] + strN # add digits to the left
#:while
return strN.rjust(width, lstStrOfDigits[0])
#:if
#:if
#:def