End-line characters from lines read from text file using Python

Question

When reading lines from a text file using python  the end-line character often needs to be truncated before processing the text  as in the following example   f   open  myFile txt    r   for line in f      line   line  -1        do something with line   Is there an elegant way or idiom for retrieving text lines without the end-line character

User · Accepted Answer

The idiomatic way to do this in Python is to use rstrip   n     for line in open  myfile txt       opened in text-mode  all EOLs are converted to   n      line   line rstrip   n       process line    Each of the other alternatives has a gotcha    file        read   splitlines   has to load the whole file in memory at once  line   line  -1  will fail if the last line has no EOL

User · Answer

Simple  Use splitlines    L   open  myFile txt    r   read   splitlines    for line in L       process line    this  line  will not have   n  character at the end

User · Answer

You may also consider using line rstrip   to remove the whitespaces at the end of your line

User · Answer

Long time ago  there was Dear  clean  old  BASIC code that could run on 16 kb core machines  like that    if  not open 1  file txt    error  Could not open  file txt  for reading  while not eof 1      line input  1 a    print a  wend close   Now  to read a file line by line  with far better hardware and software  Python   we must reinvent the wheel   def line input  file       for line in file          if line -1       n               yield line  -1          else              yield line  f   open  myFile txt    r   for line input f         do something with line   I am induced to think that something has gone the wrong way  somewhere

User · Answer

Simple  Use splitlines    L   open  myFile txt    r   read   splitlines    for line in L       process line    this  line  will not have   n  character at the end

User · Answer

What do you thing about this approach   with open filename  as data      datalines    line rstrip   r n   for line in data      for line in datalines             do something awesome      Generator expression avoids loading whole file into memory and with ensures closing the file

User · Answer

Simple  Use splitlines    L   open  myFile txt    r   read   splitlines    for line in L       process line    this  line  will not have   n  character at the end

User · Answer

You may also consider using line rstrip   to remove the whitespaces at the end of your line

User · Answer

Long time ago  there was Dear  clean  old  BASIC code that could run on 16 kb core machines  like that    if  not open 1  file txt    error  Could not open  file txt  for reading  while not eof 1      line input  1 a    print a  wend close   Now  to read a file line by line  with far better hardware and software  Python   we must reinvent the wheel   def line input  file       for line in file          if line -1       n               yield line  -1          else              yield line  f   open  myFile txt    r   for line input f         do something with line   I am induced to think that something has gone the wrong way  somewhere

User · Answer

What s wrong with your code   I find it to be quite elegant and simple   The only problem is that if the file doesn t end in a newline  the last line returned won t have a   n  as the last character  and therefore doing line   line  -1  would incorrectly strip off the last character of the line   The most elegant way to solve this problem would be to define a generator which took the lines of the file and removed the last character from each line only if that character is a newline   def strip trailing newlines file       for line in file          if line -1       n               yield line  -1          else              yield line  f   open  myFile txt    r   for line in strip trailing newlines f         do something with line

User · Answer

What s wrong with your code   I find it to be quite elegant and simple   The only problem is that if the file doesn t end in a newline  the last line returned won t have a   n  as the last character  and therefore doing line   line  -1  would incorrectly strip off the last character of the line   The most elegant way to solve this problem would be to define a generator which took the lines of the file and removed the last character from each line only if that character is a newline   def strip trailing newlines file       for line in file          if line -1       n               yield line  -1          else              yield line  f   open  myFile txt    r   for line in strip trailing newlines f         do something with line

User · Answer

What do you thing about this approach   with open filename  as data      datalines    line rstrip   r n   for line in data      for line in datalines             do something awesome      Generator expression avoids loading whole file into memory and with ensures closing the file

User · Answer

You may also consider using line rstrip   to remove the whitespaces at the end of your line

User · Answer

You may also consider using line rstrip   to remove the whitespaces at the end of your line

User · Answer

What s wrong with your code   I find it to be quite elegant and simple   The only problem is that if the file doesn t end in a newline  the last line returned won t have a   n  as the last character  and therefore doing line   line  -1  would incorrectly strip off the last character of the line   The most elegant way to solve this problem would be to define a generator which took the lines of the file and removed the last character from each line only if that character is a newline   def strip trailing newlines file       for line in file          if line -1       n               yield line  -1          else              yield line  f   open  myFile txt    r   for line in strip trailing newlines f         do something with line

User · Answer

Simple  Use splitlines    L   open  myFile txt    r   read   splitlines    for line in L       process line    this  line  will not have   n  character at the end

User · Answer

What s wrong with your code   I find it to be quite elegant and simple   The only problem is that if the file doesn t end in a newline  the last line returned won t have a   n  as the last character  and therefore doing line   line  -1  would incorrectly strip off the last character of the line   The most elegant way to solve this problem would be to define a generator which took the lines of the file and removed the last character from each line only if that character is a newline   def strip trailing newlines file       for line in file          if line -1       n               yield line  -1          else              yield line  f   open  myFile txt    r   for line in strip trailing newlines f         do something with line

[python] End-line characters from lines read from text file, using Python

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