python: csv()--io.UnsupportedOpe

目的：写入文件后直接读取文件

报错：不可读

with open('test.csv','w') as myfile: #打开文件，赋值为Myfile，准备写入
    content = csv.writer(myfile) #调用writer
    content.writerow(list_1)
    print('写入完毕')
    reader = csv.reader(myfile)
    for i in reader:
        print(i)

error:        
    for i in reader:
io.UnsupportedOperation: not readable

解决：

要先关闭文件，再次打开才能读取

with open('test.csv','w') as myfile: #打开文件，赋值为Myfile，准备写入
    content = csv.writer(myfile) #调用writer
    content.writerow(list_1)  #按行写入
    
print('写入完毕')

with open('test.csv','r') as myfile:
    reader = csv.reader(myfile)
    for i in reader:
        print(i)

另外，出现个小问题

上述代码的结果，出现了空白行

写入完毕
['1', '2', '3', '4', '5', '7']
[]
['32', '45', '65', '65', '35']
[]
['90', '5', '47']
[]

解决：

open()加上一个参数 open('test.csv','w',newline='')