Introduction
An escape sequence is a combination of characters that has a special meaning.
Escape Sequences in General
- Some characters imply a special function rather than their "normal" meaning. For example,
'
often implies the start or the end of a string. - But what if you actually mean
'
rather than a string? In that case you can escape its default meaning by prefixing it, often with a backslash (as in\'
). - Reversely,
\n
usually implies a new line indicator. In this case, the backslash escapes the default meaning ofn
(which is simplyn
). - Escape sequences thus work in two ways: they may apply a special function to a character that doesn't have one by default as in the case of (
\n
) or they may disable a special function from a character that has one by default (\'
).
Escape Sequences in SPSS
- In SPSS, quotes can be escaped by doubling them. This may be necessary when value labels or variable labels contain quotes as in
ADD VALUE LABELS v1 1 'Don''t know'.
. - If the second quote hadn't been doubled, it would have indicated the end of the value label immediately after "Don".
- An alternative here is to use double quotes around the value label and single quotes within it as in
ADD VALUE LABELS v1 1 "Don't know".
.
Escaping in Python
- In Python, escape sequences are indicated by a backslash (
\
). - The most important one may be
\n
which indicates a new line. Like so, multiple logical lines can be stacked into a single physical line. - Another escape sequence worth mentioning is
\'
for a single quote within a string. - A backslash also escapes itself so if it's really a backslash you want, double it as in
\\
. - For a demonstration of these point, run the syntax below.
Python Escape Sequence Examples
begin program.
print 'line 1\nline 2\nline 3'
print 'This is a backslash: \\'
print 'Don\'t worry be happy!'
end program.
print 'line 1\nline 2\nline 3'
print 'This is a backslash: \\'
print 'Don\'t worry be happy!'
end program.