mvpa2.base.info.StringIO

class mvpa2.base.info.StringIO(buf='')

class StringIO([buffer])

When a StringIO object is created, it can be initialized to an existing string by passing the string to the constructor. If no string is given, the StringIO will start empty.

The StringIO object can accept either Unicode or 8-bit strings, but mixing the two may take some care. If both are used, 8-bit strings that cannot be interpreted as 7-bit ASCII (that use the 8th bit) will cause a UnicodeError to be raised when getvalue() is called.

Methods

close()

Free the memory buffer.

flush()

Flush the internal buffer

getvalue()

Retrieve the entire contents of the “file” at any time before the StringIO object’s close() method is called.

The StringIO object can accept either Unicode or 8-bit strings, but mixing the two may take some care. If both are used, 8-bit strings that cannot be interpreted as 7-bit ASCII (that use the 8th bit) will cause a UnicodeError to be raised when getvalue() is called.

isatty()

Returns False because StringIO objects are not connected to a tty-like device.

next()

A file object is its own iterator, for example iter(f) returns f (unless f is closed). When a file is used as an iterator, typically in a for loop (for example, for line in f: print line), the next() method is called repeatedly. This method returns the next input line, or raises StopIteration when EOF is hit.

read(n=-1)

Read at most size bytes from the file (less if the read hits EOF before obtaining size bytes).

If the size argument is negative or omitted, read all data until EOF is reached. The bytes are returned as a string object. An empty string is returned when EOF is encountered immediately.

readline(length=None)

Read one entire line from the file.

A trailing newline character is kept in the string (but may be absent when a file ends with an incomplete line). If the size argument is present and non-negative, it is a maximum byte count (including the trailing newline) and an incomplete line may be returned.

An empty string is returned only when EOF is encountered immediately.

Note: Unlike stdio’s fgets(), the returned string contains null characters (‘0’) if they occurred in the input.

readlines(sizehint=0)

Read until EOF using readline() and return a list containing the lines thus read.

If the optional sizehint argument is present, instead of reading up to EOF, whole lines totalling approximately sizehint bytes (or more to accommodate a final whole line).

seek(pos, mode=0)

Set the file’s current position.

The mode argument is optional and defaults to 0 (absolute file positioning); other values are 1 (seek relative to the current position) and 2 (seek relative to the file’s end).

There is no return value.

tell()

Return the file’s current position.

truncate(size=None)

Truncate the file’s size.

If the optional size argument is present, the file is truncated to (at most) that size. The size defaults to the current position. The current file position is not changed unless the position is beyond the new file size.

If the specified size exceeds the file’s current size, the file remains unchanged.

write(s)

Write a string to the file.

There is no return value.

writelines(iterable)

Write a sequence of strings to the file. The sequence can be any iterable object producing strings, typically a list of strings. There is no return value.

(The name is intended to match readlines(); writelines() does not add line separators.)