leading or trailing characterspython
'$out_file1'
]]>
**What it does**
Trims specified number of characters from a dataset or a given column (if dataset is tab-delimited).
-----
**Example 1**
Trimming this dataset::
1234567890
abcdefghijk
by setting **Trim from the beginning up to this position** to *2* and **Remove everything from this position to the end** to *6* will produce::
23456
bcdef
-----
**Example 2**
Trimming column 2 of this dataset::
abcde 12345 fghij 67890
fghij 67890 abcde 12345
by setting **Trim content of this column only** to *2*, **Trim from the beginning up to this position** to *2*, and **Remove everything from this position to the end** to *4* will produce::
abcde 234 fghij 67890
fghij 789 abcde 12345
-----
**Example 3**
Trimming column 2 of this dataset::
abcde 12345 fghij 67890
fghij 67890 abcde 12345
by setting **Trim content of this column only** to *2*, **Trim from the beginning up to this position** to *2*, and **Remove everything from this position to the end** to *-2* will produce::
abcde 23 fghij 67890
fghij 78 abcde 12345
----
**Trimming FASTQ datasets**
This tool can be used to trim sequences and quality strings in FASTQ datasets. This is done by selected *Yes* from the **Is input dataset in FASTQ format?** dropdown. If set to *Yes*, the tool will skip all even numbered lines (see warning below). For example, trimming last 5 bases of this dataset::
@081017-and-081020:1:1:1715:1759
GGACTCAGATAGTAATCCACGCTCCTTTAAAATATC
+
II#IIIIIII$5+.(9IIIIIII$%*$G$A31I&&B
can be done by setting **Remove everything from this position to the end** to 31::
@081017-and-081020:1:1:1715:1759
GGACTCAGATAGTAATCCACGCTCCTTTAAA
+
II#IIIIIII$5+.(9IIIIIII$%*$G$A3
**Note** that headers are skipped.
.. class:: warningmark
**WARNING:** This tool will only work on properly formatted FASTQ datasets where (1) each read and quality string occupy one line and (2) '@' (read header) and "+" (quality header) lines are evenly numbered like in the above example.