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authorEzio Melotti <ezio.melotti@gmail.com>2013-04-15 16:08:31 (GMT)
committerEzio Melotti <ezio.melotti@gmail.com>2013-04-15 16:08:31 (GMT)
commited3cd7e445e7be413d1b454471454f7ff9f21f1f (patch)
tree146e7c94d722abcfe6fc1a693be999328ebdf71d
parent45fe62dc9c406f1c2520867d99e557ac227f9bfb (diff)
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#13510: clarify that f.readlines() is note necessary to iterate over a file. Patch by Dan Riti.
-rw-r--r--Doc/library/io.rst3
-rw-r--r--Doc/tutorial/inputoutput.rst19
-rw-r--r--Misc/ACKS1
3 files changed, 8 insertions, 15 deletions
diff --git a/Doc/library/io.rst b/Doc/library/io.rst
index a8d5fe3..8f3964f 100644
--- a/Doc/library/io.rst
+++ b/Doc/library/io.rst
@@ -298,6 +298,9 @@ I/O Base Classes
to control the number of lines read: no more lines will be read if the
total size (in bytes/characters) of all lines so far exceeds *hint*.
+ Note that it's already possible to iterate on file objects using ``for
+ line in file: ...`` without calling ``file.readlines()``.
+
.. method:: seek(offset, whence=SEEK_SET)
Change the stream position to the given byte *offset*. *offset* is
diff --git a/Doc/tutorial/inputoutput.rst b/Doc/tutorial/inputoutput.rst
index c804e25..ef22459 100644
--- a/Doc/tutorial/inputoutput.rst
+++ b/Doc/tutorial/inputoutput.rst
@@ -300,18 +300,8 @@ containing only a single newline. ::
>>> f.readline()
''
-``f.readlines()`` returns a list containing all the lines of data in the file.
-If given an optional parameter *sizehint*, it reads that many bytes from the
-file and enough more to complete a line, and returns the lines from that. This
-is often used to allow efficient reading of a large file by lines, but without
-having to load the entire file in memory. Only complete lines will be returned.
-::
-
- >>> f.readlines()
- ['This is the first line of the file.\n', 'Second line of the file\n']
-
-An alternative approach to reading lines is to loop over the file object. This is
-memory efficient, fast, and leads to simpler code::
+For reading lines from a file, you can loop over the file object. This is memory
+efficient, fast, and leads to simple code::
>>> for line in f:
... print(line, end='')
@@ -319,9 +309,8 @@ memory efficient, fast, and leads to simpler code::
This is the first line of the file.
Second line of the file
-The alternative approach is simpler but does not provide as fine-grained
-control. Since the two approaches manage line buffering differently, they
-should not be mixed.
+If you want to read all the lines of a file in a list you can also use
+``list(f)`` or ``f.readlines()``.
``f.write(string)`` writes the contents of *string* to the file, returning
the number of characters written. ::
diff --git a/Misc/ACKS b/Misc/ACKS
index 56d140e..a7837a4 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1003,6 +1003,7 @@ Nicholas Riley
Jean-Claude Rimbault
Vlad Riscutia
Wes Rishel
+Dan Riti
Juan M. Bello Rivas
Davide Rizzo
Anthony Roach