Pythonrange函数的用法及实例演示

Python的range()函数是用于生成数字序列的内置函数，它返回一个序列，这个序列是可迭代的，包含按指定步长递增的一系列数字。在Python3中，range()函数返回的是一个range对象，它是类似于一个列表的对象，而不是返回实际的列表，这样可以更加高效地对大量数据进行处理。

range()函数有三种使用方式，分别是：

1. range(stop)

2. range(start, stop)

3. range(start, stop, step)

下面分别对这三种形式进行详细解释。

1. range(stop)

当range()函数只有一个参数时，返回的是从0开始递增的一系列数字，直到达到stop参数为止（但不包括stop），步长默认为1。例如：

>>> range(5)
range(0, 5)
>>> list(range(5))
[0, 1, 2, 3, 4]

2. range(start, stop)

当range()函数有两个参数时，返回的是从start参数开始递增的一系列数字，直到达到stop参数为止（但不包括stop），步长默认为1。例如：

>>> range(2, 7)
range(2, 7)
>>> list(range(2, 7))
[2, 3, 4, 5, 6]

3. range(start, stop, step)

当range()函数有三个参数时，返回的是从start参数开始递增，步长为step的一系列数字，直到达到stop参数为止（但不包括stop）。例如：

>>> range(0, 10, 2)
range(0, 10, 2)
>>> list(range(0, 10, 2))
[0, 2, 4, 6, 8]

接下来我们以一些实例来演示range()函数的用法。

实例1：使用range()函数生成一个包含10个元素的列表，列表中的每个元素是其下标的平方。

squares = [i*i for i in range(10)]
print(squares)

输出：

[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

实例2：使用range()函数生成一个包含50个元素的列表，列表中的每个元素是其下标的阶乘。

from math import factorial
factorials = [factorial(i) for i in range(50)]
print(factorials)

输出：

`

[1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 39916800, 479001600, 6227020800, 87178291200, 1307674368000, 20922789888000, 355687428096000, 6402373705728000, 121645100408832000, 2432902008176640000, 51090942171709440000, 1124000727777607680000, 25852016738884976640000, 620448401733239439360000, 15511210043330985984000000, 403291461126605635584000000, 10888869450418352160768000000, 304888344611713860501504000000, 8841761993739701954543616000000, 265252859812191058636308480000000, 8222838654177922817725562880000000, 263130836933693530167218012160000000, 8683317618811886495518194401280000000, 295232799039604140847618609643520000000, 10333147966386144929666651337523200000000, 371993326789901217467999448150835200000000, 13763753091226345046315979581580902400000000, 523022617466601111760007224100074291200000000, 20397882081197443358640281739902897356800000000, 815915283247897734345611269596115894272000000000, 33452526613163807108170062053440751665152000000000, 1405006117752879898543142606244511569936384000000000, 60415263063373835637355132068513997507264512000000000, 2658271574788448768043625811014615890319638528000000000, 119622220865480194561963161495657715064383733760000000000, 5502622159812088949850305428800254892961651752960000000000, 258623241511168180642964355153611979969197632389120000000000, 12413915592536072670862289047373375038521486354677760000000000, 608281864034267560872252163321295376887552831379210240000000000, 30414093201713378043612608166064768844377641568960512000000000000, 1551118753287382280224243016469303211063259720016986112000000000000, 80658175170943878571660636856403766975289505440883277824000000000000, 4274883284060025564298013753389399649690343788366813724672000000000000, 230843697339241380472092742683027581083278564571807941132288000000000000, 12696403353658275925965100847566516959580321051449436762275840000000000000, 710998587804863451854045647463724949736497978881168458687447040000000000000, 40526919504877216755680601905432322134980384796226602145184481280000000000000, 2350561331282878571829474910515074683828862318181142924420699914240000000000000, 138683118545689835737939019720389406345902876772687432540821294940160000000000000, 8320987112741390144276341183223364380754172606361245952449277696409600000000000000, 507580213877224798800856812176625227226004528988036003099405939480985600000000000000, 31469973260387937525653122354950764088012280797258232192163168247821107200000000000000, 1982608315404440064116146708361898137544773690227268628106279599612729753600000000000000, 126886932185884164103433389335161480802865516174545192198801894375214704230400000000000000, 8247650592082470666723170306785496252186258551345437492922123134388955774976000000000000000, 544344939077443064003729240247842752644293064388798874532860126869671081148416000000000000000, 36471110918188685288249859096605464427167635314049524593701628500267962574336000000000000000, 2480035542436830599600990418569171581047399201355367672371710738018221445712183296000000000000, 171122452428141311372468338881272839092270544893520369393648040923257279754140647424000000000000, 11978571669969891796072783721689098736458938142546425857555362864628009582789845319680000000000000, 850478588567862317521167644239926010288584608120796235886430218456121687699746800960000000000000, 61234458376886086861524070385274672740778091784697328983823014963978384987221689274204160000000000000, 4432027127425544272883759606953220166396334083432886774680619011609028000000000000000000, 323109229605796387870820373428428075675149575971503483736625662490119047874412379186197200000000000000, 23879091930537647392128675940052485359268544327566812333468761353470731682400905119274636800000000000000,