TypeError expected a character buffer object - while trying to save integer to textfile

Question

I m trying to make a very simple  counter  that is supposed to keep track of how many times my program has been executed   First  I have a textfile that only includes one character  0  Then I open the file  parse it as an int  add 1 to the value  and then try to return it to the textfile   f   open  testfile txt    r    x   f read   y   int x    1 print y  f write y  f close     I d like to have y overwrite the value in the textfile  and then close it    But all I get is TypeError  expected a character buffer object   Edit   Trying to parse y as a string   f write str y     gives  IOError   Errno 0  Error

User · Accepted Answer

Have you checked the docstring of write    It says      write str  -  None   Write string str to file       Note that due to buffering  flush   or close   may be needed before   the file on disk reflects the data written    So you need to convert y to str first   Also note that the string will be written at the current position which will be at the end of the file  because you ll already have read the old value  Use f seek 0  to get to the beginning of the file    Edit  As for the IOError  this issue seems related  A cite from there      For the modes where both read and writing  or appending  are allowed    those which include a     sign   the stream should be flushed  fflush    or repositioned  fseek  fsetpos  rewind  between either a reading   operation followed by a writing operation or a writing operation   followed by a reading operation    So  I suggest you try f seek 0  and maybe the problem goes away

User · Answer

Just try the code below   As I see you have inserted  r   or this command open the file in read mode so you are not able to write into it  so you have to open file in write mode  w  if you want to overwrite  the file contents and write new data  otherwise you can append data to file by using  a   I hope this will help     f   open  testfile txt    w    just put  w  if you want to write to the file   x   f readlines    this command will read file lines  y   int x  1  print y z   str y   making data as string to avoid buffer error f write z   f close

User · Answer

from   future   import with statement with open  file txt   r    as f      counter   str int f read   strip    1      f seek 0      f write counter

[python] TypeError: expected a character buffer object - while trying to save integer to textfile

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