Read only the first line of a file

Question

How would you get only the first line of a file as a string with Python

User · Answer

This should do it   f   open  myfile txt   first   f readline

User · Answer

Use the  readline   method  Python 2 docs  Python 3 docs    with open  myfile txt   as f      first line   f readline     Some notes    As noted in the docs  unless it is the only line in the file  the string returned from f readline   will contain a trailing newline  You may wish to use f readline   strip   instead to remove the newline  The with statement automatically closes the file again when the block ends  The with statement only works in Python 2 5 and up  and in Python 2 5 you need to use from   future   import with statement In Python 3 you should specify the file encoding for the file you open  Read more

User · Answer

infile   open  filename txt    r   firstLine   infile readline

User · Answer

first line   next open filename

User · Answer

f1   open  input1 txt    r   print f1 readline

User · Answer

fline open  myfile   readline   rstrip

User · Answer

Lots of other answers here  but to answer precisely the question you asked  before  MarkAmery went and edited the original question and changed the meaning     gt  gt  gt  f   open  myfile txt    gt  gt  gt  data   f read    gt  gt  gt    I m assuming you had the above before asking the question  gt  gt  gt  first line   data split   n   1  0    In other words  if you ve already read in the file  as you said   and have a big block of data in memory  then to get the first line from it efficiently  do a split   on the newline character  once only  and take the first element from the resulting list   Note that this does not include the  n character at the end of the line  but I m assuming you don t want it anyway  and a single-line file may not even have one    Also note that although it s pretty short and quick  it does make a copy of the data  so for a really large blob of memory you may not consider it  efficient    As always  it depends

User · Answer

To go back to the beginning of an open file and then return the first line  do this   my file seek 0  first line   my file readline

[python] Read only the first line of a file?

Examples related to python

Examples related to file