• 列表的系列操作(python)


    除了定义和切片外,这里总结下系列的操作:

    # hanbb come on!
    names = ["hbb",'tian','bao','cheng']
    
    #Add
    names.append("new")
    print(names)             #['hbb', 'tian', 'bao', 'cheng', 'new']
    
    # insert
    #names.insert(1,before 2)              #invalid syntax
    names.insert(1,"before 1")
    print(names)            #['hbb', 'before 1','tian',  'bao', 'cheng', 'new']
    names.insert(2,'behind 1')                                                #写在哪,插在哪
    print(names)            # ['hbb', 'behind 1', 'before 2', 'tian', 'bao', 'cheng', 'new']
    
    # revise
    names [0] = "忍你很久了"
    print(names)            # ['忍你很久了', 'before 1', 'behind 1', 'tian', 'bao', 'cheng', 'new']
    
    # delete
    del names [1]
    print(names)            # ['忍你很久了', 'behind 1', 'tian', 'bao', 'cheng', 'new']
    # del names['bao']                    #list indices must be integers or slices, not str
    
    # names.del                          # no have this operation
    # names.remove(2)                    # list.remove(x): x not in list
    names.remove("tian")
    print(names)            # ['忍你很久了', 'behind 1', 'bao', 'cheng', 'new']
    
    names.pop(2)            # ['忍你很久了', 'behind 1', 'cheng', 'new']
    print(names)
    names.pop()                          # delete the last one
    print(names)            # ['忍你很久了', 'behind 1', 'cheng']
    
    # extend
    names_2 = ["cao","hu","zhuo"]
    
    names.extend(names_2)
    print(names)             # ['忍你很久了', 'behind 1', 'cheng', 'cao', 'hu', 'zhuo']
    
    # copy
    names_3 = names.copy()
    print(names_3)           # ['忍你很久了', 'behind 1', 'cheng', 'cao', 'hu', 'zhuo']
    
    # count
    # names.count()                            # count() takes exactly one argument (0 given)
    
    #print(names.count(cao))                   #   name 'cao' is not defined
    print(names.count("cao"))                 #  统计出现的次数
    
    
    # sort
    names.insert(-1,"666")
    names.insert(-1,"b88")
    print(names)              # ['忍你很久了', 'behind 1', 'cheng', 'cao', 'hu', '666', 'b88', 'zhuo']
    names.sort()
    print(names)              # ['666', 'b88', 'behind 1', 'cao', 'cheng', 'hu', 'zhuo', '忍你很久了']
    # Reverse
    names.reverse()
    print(names)              # ['忍你很久了', 'zhuo', 'hu', 'cheng', 'cao', 'behind 1', 'b88', '666']
    
    #  获取下标(位置)
    #  names.index()                             # return first index of value. Raises ValueError if the value is not present.
    print(names.index("hu"))  # 2
    
    names.insert(2,"hu")      
    print(names)              # ['忍你很久了', 'zhuo', 'hu', 'hu', 'cheng', 'cao', 'behind 1', 'b88', '666']
    print(names.index("hu")) # 2

    可以分为两种情况进行总结:

    总结1:单元元素操作

    names = ["hbb",'tian','bao','cheng']
    # the operation of single element:
    names.append("xiaoqi")        # add to the last
    names.insert(2,"bb8")         # inset one element to target location.
    
    names.remove("bao")           # remove one element
    names.pop()                   # remove the last element
    names.pop(1)                  # remove element according to it location
    print(names.count("cheng"))   # 统计某个元素出现的次数
    print(names.index("cheng"))   # 获取某个元素的位置(下标),第一次出现
    
    names [2] = "我要上位"         # 将某位置的元素换掉
    names ["hbb"] = "HBB" # 只能根据位置来操作,很忧伤 del names [1] # 根据位置删除

    总结1:整个列表的操作

    # the operation of entired list
    names_2 = names.copy()        # 复制列表
    names_3 = ['1','2'] names.extend(names_3) # 扩展列表 names.reverse() # 翻转列表 names.sort() # 排序

    总结2:多数情况均是以names.XXXX()进行操作,有几个不是:

    names = ["hbb",'tian','bao','cheng']
    # the operation of single element:
    
    names [2] = "我要上位"      # 更换操作
    del names [1] # 可以用 names.remove( )代替 names.pip (1)
    # the operation of entired list names_3 = ['1','2'] # difine
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  • 原文地址:https://www.cnblogs.com/hanbb/p/7206311.html
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