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  • Simple Tips for Collection in Python

      I believe that the following Python code is really not hard to understand. But I think we should use these tips

    in our own code.

    def main():
        #To judge whether a list is empty. We can use "if list0" instead of "if len(list0)". But we must be aware that [] is not None and [] is not False.
        list1 = [10, 12, 23, 24]
        list2 = []
    
        if list1:
            print "list1: {}".format(list1)
        else:
            print "list1 is an empty list: {}".format(list1)
    
        if list2:
            print "list2: {}".format(list2)
        else:
            print "list2 is an empty list: {}".format(list2)
    
        #[] is not None. [] is not False.
        print list2==None     #False
        print list2==False    #False
        print list2 is None   #False
        print list2 is False  #False
    
        #Get the index while traverse a list.
        for index, value in enumerate(list1):
            print "index: {}, value: {}".format(index, value)
    
    if __name__ == '__main__':
        main()
    else:
        print "Being imported as a module."

    Output:

    lxw Practice$ python collectionTips.py 
    list1: [10, 12, 23, 24]
    list2 is an empty list: []
    False
    False
    False
    False
    index: 0, value: 10
    index: 1, value: 12
    index: 2, value: 23
    index: 3, value: 24
    lxw Practice$ 

      There are some other tips in this article.

    Reference:

    Python Collection小技巧:https://linuxtoy.org/archives/python-collection-tips.html

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  • 原文地址:https://www.cnblogs.com/lxw0109/p/tips-for-collection.html
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