将另一个文件中的数据附加到文件的开头答案

【问题标题】：Appending Data from Another File to the Beginning of a File将另一个文件中的数据附加到文件的开头
【发布时间】：2021-03-05 04:53:36
【问题描述】：

有没有办法将file1的内容附加到file2的开头？我试过用这个方法，但它似乎不起作用

def main():
    """The program does the following:
    - it inserts all the content from file2.txt to the beginning of file1.txt
    
    Note: After execution of the your program, only file1.txt is updated, file2.txt does not change."""
    #WRITE YOUR PROGRAM HERE

    

#Call the main() function
if __name__ == '__main__':
    main()
    f = open('file1.txt', 'r')
    f1 = open('file2.txt', 'r')
    def insert(file2, string):
        with open('file2.txt','r') as f:
            with open('file1.txt','w') as f1: 
                f1.write(string)
                f1.write(f.read())
        os.rename('file1.txt',file2)
    
    # closing the files 
    f.close() 
    f1.close()

【问题讨论】：

这能回答你的问题吗？ Prepend line to beginning of a file

标签： python file append

【解决方案1】：

首先，您需要将这些文件的内容分配给变量。

string1 = ""
string2 = ""
with open('file1.txt', 'r') as file:
    string1 = file.read().replace('\n', '')
    file.close()

with open('file2.txt', 'r') as file:
    string2 = file.read().replace('\n', '')
    file.close()

然后与+运算符结合

string3 = string1 + " " + string2
with open("file3.txt", "w") as file:
    text_file.write("%s" % string3)
    file.close()

完成。

更新，因为您需要将file2附加到file1的开头，做

string3 = string2 + " " + string1

【讨论】：

【解决方案2】：

试试这个代码：

data = open("file.txt", "r").read()
data = data.split("\n")
new_data = #what you want to add
new_data = new_data.split("\n")
for elem in new_data:
    data.insert(0, elem)
f = open("file.txt", "a")
f.truncate()
for elem in data:
    f.write(elem)
f.close()

【讨论】：