f = lambda x,y,z: (x+i*z for i in range(int((y-x)/z)))

上面不需要借助任何库就可以做分数步。

我认为NumPy有点过头了。

[p/10 for p in range(0, 10)]
[0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9]

一般来说，要做阶跃1/x直到y

x=100
y=2
[p/x for p in range(0, int(x*y))]
[0.0, 0.01, 0.02, 0.03, ..., 1.97, 1.98, 1.99]

(1/x在我测试时产生的舍入噪声更少)。

scipy有一个内置的函数arange，它泛化了Python的range()构造函数，以满足您对浮点数处理的需求。

从scipy进口安排

令人惊讶的是，在Python 3文档中还没有人提到推荐的解决方案:

参见: linspace菜谱展示了如何实现适用于浮点应用程序的惰性版本的range。

一旦定义，recipe就很容易使用，不需要numpy或任何其他外部库，只需要numpy.linspace()这样的函数。注意，第三个num参数指定所需值的数量，而不是step参数，例如:

print(linspace(0, 10, 5))
# linspace(0, 10, 5)
print(list(linspace(0, 10, 5)))
# [0.0, 2.5, 5.0, 7.5, 10]

下面我引用了Andrew Barnert的完整Python 3配方的修改版本:

import collections.abc
import numbers

class linspace(collections.abc.Sequence):
    """linspace(start, stop, num) -> linspace object

    Return a virtual sequence of num numbers from start to stop (inclusive).

    If you need a half-open range, use linspace(start, stop, num+1)[:-1].
    """
    def __init__(self, start, stop, num):
        if not isinstance(num, numbers.Integral) or num <= 1:
            raise ValueError('num must be an integer > 1')
        self.start, self.stop, self.num = start, stop, num
        self.step = (stop-start)/(num-1)
    def __len__(self):
        return self.num
    def __getitem__(self, i):
        if isinstance(i, slice):
            return [self[x] for x in range(*i.indices(len(self)))]
        if i < 0:
            i = self.num + i
        if i >= self.num:
            raise IndexError('linspace object index out of range')
        if i == self.num-1:
            return self.stop
        return self.start + i*self.step
    def __repr__(self):
        return '{}({}, {}, {})'.format(type(self).__name__,
                                       self.start, self.stop, self.num)
    def __eq__(self, other):
        if not isinstance(other, linspace):
            return False
        return ((self.start, self.stop, self.num) ==
                (other.start, other.stop, other.num))
    def __ne__(self, other):
        return not self==other
    def __hash__(self):
        return hash((type(self), self.start, self.stop, self.num))

我的版本使用原始的范围函数来创建移位的乘法指标。这允许原始的range函数使用相同的语法。 我做了两个版本，一个使用浮点，一个使用Decimal，因为我发现在某些情况下，我想避免浮点算法引入的舍入漂移。

它与range/xrange中的空集结果一致。

仅向任何一个函数传递一个数值都会将标准范围输出返回到输入参数的整数上限值(因此如果给它5.5，它将返回range(6))。

编辑:下面的代码现在可以在pypi: Franges上作为包使用

## frange.py
from math import ceil
# find best range function available to version (2.7.x / 3.x.x)
try:
    _xrange = xrange
except NameError:
    _xrange = range

def frange(start, stop = None, step = 1):
    """frange generates a set of floating point values over the 
    range [start, stop) with step size step

    frange([start,] stop [, step ])"""

    if stop is None:
        for x in _xrange(int(ceil(start))):
            yield x
    else:
        # create a generator expression for the index values
        indices = (i for i in _xrange(0, int((stop-start)/step)))  
        # yield results
        for i in indices:
            yield start + step*i

## drange.py
import decimal
from math import ceil
# find best range function available to version (2.7.x / 3.x.x)
try:
    _xrange = xrange
except NameError:
    _xrange = range

def drange(start, stop = None, step = 1, precision = None):
    """drange generates a set of Decimal values over the
    range [start, stop) with step size step

    drange([start,] stop, [step [,precision]])"""

    if stop is None:
        for x in _xrange(int(ceil(start))):
            yield x
    else:
        # find precision
        if precision is not None:
            decimal.getcontext().prec = precision
        # convert values to decimals
        start = decimal.Decimal(start)
        stop = decimal.Decimal(stop)
        step = decimal.Decimal(step)
        # create a generator expression for the index values
        indices = (
            i for i in _xrange(
                0, 
                ((stop-start)/step).to_integral_value()
            )
        )  
        # yield results
        for i in indices:
            yield float(start + step*i)

## testranges.py
import frange
import drange
list(frange.frange(0, 2, 0.5)) # [0.0, 0.5, 1.0, 1.5]
list(drange.drange(0, 2, 0.5, precision = 6)) # [0.0, 0.5, 1.0, 1.5]
list(frange.frange(3)) # [0, 1, 2]
list(frange.frange(3.5)) # [0, 1, 2, 3]
list(frange.frange(0,10, -1)) # []

sign = lambda x: (1, -1)[x < 0]
def frange(start, stop, step):
    i = 0
    r=len(str(step).split('.')[-1])
    args=(start,stop,step)
    if not step :return []
    if all(int(i)==float(i) for i in args):
        start,stop,step=map(int,args)
    if sign(step)==1:
        while start + i * step < stop:
            yield round(start + i * step,r)
            i += 1
    else:
        while start + i * step > stop:
            yield round(start + i * step,r)
            i += 1