相关疑难解决方法(0)

list.append()是添加到列表末尾的明显选择.这是对失踪人员的合理解释list.prepend().假设我的列表很短并且性能问题可以忽略不计,那就是

list.insert(0, x)

要么

list[0:0] = [x]

地道？

我正在学习Python 3.4.2中的函数和类,我从这段代码片段的输出中得到了一些偏见:

print("This program will collect your demographic information and output it")
print ("")

class Demographics:   #This class contains functions to collect demographic info 

    def phoneFunc():  #This function will collect user's PN, including area code
        phoneNum = str(input("Enter your phone number, area code first "))
        phoneNumList = []
        phoneNumList[:0] = phoneNum
        #phoneNumList.insert(0, phoneNum) this is commented out b/c I tried this and it made the next two lines insert the dash incorrectly

        phoneNumList.insert(3, '-')
        phoneNumList.insert(7, '-')
        print(*phoneNumList)

x = Demographics …

我在 Python 中有一个名为“AllLines”的二维数组

[['Suppliers', 'Spend', 'Test Field\n'], 
 ['Dell Inc', '9000', '1\n'], 
 ['Dell Computers', '9000', '2\n'], 
 ['HBC Corp', '9000', '3\n'], 
 ['HBC INC', '9000', '4']]

所以，它是一个数组中的一个数组。我需要将项目附加到内部数组。给我这个：

[['NEW','Suppliers', 'Spend', 'Test Field\n'], 
 ['N-E-W','Dell Inc', '9000', '1\n'], 
 ['N-E-W---','Dell Computers', '9000', '2\n'], 
 ['N-E---W','HBC Corp', '9000', '3\n'], 
 ['N-W-W','HBC INC', '9000', '4']]

如何实现向内部数组添加新项目？