请注意，Python不会将数字写入文本文件，如果要将数字写入文本文件，需要用str函数对其进行转换。
如：
num1=100000
with open('test.txt','w') as file1:
  file1.write(str(num1))
  file1.close()
print("写入完成")

with open('test.txt') as file2:
  print("文件内容：")
  for line in file2:
      print(line)

正常写入的文本是不会自动加换行符的，需手动添加。
如：
with open('test.txt','w') as file1:
  file1.write("hello,world!")
  file1.write("this is second line.")
  file1.close()
print("写入完成")
with open('test.txt') as file2:    
  print("文件内容：")
  for line in file2:
      print(line)

如果想换行可以加换行符
with open('test.txt','w') as file1:
  file1.write("hello,world!\n")
  file1.write("this is second line.\n")
  file1.close()
print("写入完成")

with open('test.txt') as file2: 
  print("文件内容：")    
  for line in file2:
      print(line)

附加模式
如果您不想清空原有文件，可以使用附加模式。
如：
with open('test.txt','a') as file1:
  file1.write("hello,world!\n")
  file1.write("this is second line.\n")
  file1.close()
print("写入完成")

with open('test.txt') as file2: 
  print("文件内容：")    
  for line in file2:
      print(line)

创建一个空文件
with open(‘test6.txt‘,’w’) as file1:
  file1.write("hello,world!\n")
  file1.write("this is second line.\n")
  file1.close()
print("写入完成")

with open('test6.txt') as file2: 
  print("文件内容：")    
  for line in file2:
      print(line)