Remove the newline character in a list read from a file

Question

I have a simple program that takes an ID number and prints information for the person matching the ID  The information is stored in a  dat file  with one ID number per line   The problem is that my program is also reading the newline character  n from the file  I have tried the  name  split   method  but this doesn t seem to work for a list   My program   from time import localtime  strftime  files   open  grades dat   request   open  requests dat    w   lists   files readlines   grades       for i in range len lists        grades append lists i  split        cont    y   while cont     y  or cont     Y       answer   raw input  Please enter the Student I D  of whom you are looking         for i in range len grades            if answer    grades i  0               print grades i  1           grades i  2         6    grades i  0         6    grades i  3              time   strftime   a   b  d  Y  H  M  S   localtime                print time             print  Exams -     grades i  11           grades i  12           grades i  13              print  Homework -     grades i  4           grades i  5           grades i  6           grades i  7          grades i  8           grades i  9           grades i  10              total   int grades i  4     int grades i  5     int grades i  6     int grades i  7     int grades i  8     int grades i  9     int grades i  10     int grades i  11     int grades i  12     int grades i  13               print  Total points earned -     str total              grade   float total    550             grade   grade   100             if grade  gt   90                  print  Grade      str grade       that is equal to an A               elif grade  gt   80 and grade  lt  90                  print  Grade      str    2f   grade       that is equal to a B               elif grade  gt   70 and grade  lt  80                  print  Grade      str    2f   grade       that is equal to a C               elif grade  gt   60 and grade  lt  70                  print  Grade      str    2f   grade       that is equal to a D               else                  print  Grade      str    2f   grade       that is equal to an F               request write grades i  0          grades i  1           grades  i  2                                    time              request write   n         print     cont   raw input  Would you like to search again      if cont     y  or cont     Y       print  Goodbye

User · Answer

You can use the strip   function to remove trailing  and leading  whitespace  passing it an argument will let you specify which whitespace   for i in range len lists        grades append lists i  strip   n        It looks like you can just simplify the whole block though  since if your file stores one ID per line grades is just lists with newlines stripped   Before  lists   files readlines   grades       for i in range len lists        grades append lists i  split         After  grades    x strip   for x in files readlines       the above is a list comprehension     Finally  you can loop over a list directly  instead of using an index   Before  for i in range len grades          do something with grades i    After  for thisGrade in grades        do something with thisGrade

User · Answer

You want the String strip s   chars   function  which will strip out whitespace characters or whatever characters  such as   n   you specify in the chars argument   See http   docs python org release 2 3 lib module-string html

User · Answer

You could actually put the newlines to good use by reading the entire file into memory as a single long string and then use them to split that into the list of grades   with open  grades dat   as input      grades    line split      for line in input read   splitlines    etc

User · Answer

str strip   returns a string with leading trailing whitespace removed   lstrip and  rstrip for only leading and trailing respectively   grades append lists i  rstrip   n   split

User · Answer

Here are various optimisations and applications of proper Python style to make your code a lot neater  I ve put in some optional code using the csv module  which is more desirable than parsing it manually  I ve also put in a bit of namedtuple goodness  but I don t use the attributes that then provides  Names of the parts of the namedtuple are inaccurate  you ll need to correct them   import csv from collections import namedtuple from time import localtime  strftime    Method one  reading the file into lists manually  less desirable  with open  grades dat   as files      grades     e strip   for e in s split       for s in files     Method two  using csv and namedtuple StudentRecord   namedtuple  StudentRecord    id  lastname  firstname  something  homework1  homework2  homework3  homework4  homework5  homework6  homework7  exam1  exam2  exam3   grades   map StudentRecord  make  csv reader open  grades dat       Now you could have student id  student lastname  etc    Skipping the namedtuple  you could do grades   map tuple  csv reader open  grades dat      request   open  requests dat    w   cont    y   while cont lower       y       answer   raw input  Please enter the Student I D  of whom you are looking         for student in grades          if answer    student 0               print   s   s       s       s     student 1   student 2   student 0   student 3               time   strftime   a   b  d  Y  H  M  S   localtime                print time             print  Exams -  s   s   s    student 11 14              print  Homework -  s   s   s   s   s   s   s    student 4 11              total   sum int x  for x in student 4 14               print  Total points earned -  d    total             grade   total   5 5             if grade  gt   90                  letter    an A              elif grade  gt   80                  letter    a B              elif grade  gt   70                  letter    a C              elif grade  gt   60                  letter    a D              else                  letter    an F               if letter    an A                   print  Grade   s  that is equal to  s      grade  letter              else                  print  Grade    2f  that is equal to  s      grade  letter               request write   s  s   s  s n     student 0   student 1   student 2   time         print     cont   raw input  Would you like to search again      print  Goodbye

[python] Remove the newline character in a list read from a file

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