本文实例讲述了python中dir函数用法。分享给大家供大家参考。具体分析如下:
dir 函数返回任意对象的属性和方法列表,
包括模块对象、函数对象、字符串对象、列表对象、字典对象 ...... 相当多的东西。
dir函数示例:
>>> li = [] >>> dir(li) ['append','count','extend','index','insert', 'pop','remove','reverse','sort'] >>> d = {} >>> dir(d) ['clear','copy','get','has_key','items','keys','setdefault','update','values']
希望本文所述对大家的Python程序设计有所帮助。

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Useaforloopwheniteratingoverasequenceorforaspecificnumberoftimes;useawhileloopwhencontinuinguntilaconditionismet.Forloopsareidealforknownsequences,whilewhileloopssuitsituationswithundeterminediterations.

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Pythonisbothinterpretedandcompiled.1)It'scompiledtobytecodeforportabilityacrossplatforms.2)Thebytecodeistheninterpreted,allowingfordynamictypingandrapiddevelopment,thoughitmaybeslowerthanfullycompiledlanguages.

Forloopsareidealwhenyouknowthenumberofiterationsinadvance,whilewhileloopsarebetterforsituationswhereyouneedtoloopuntilaconditionismet.Forloopsaremoreefficientandreadable,suitableforiteratingoversequences,whereaswhileloopsoffermorecontrolandareusefulf

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