try:
    from Bio import SeqIO
    from Bio.Alphabet import IUPAC
except ImportError as e:
    print('ERROR: {}'.format(e.msg))
    exit(1)

def load_file(filename, file_format="fasta"):
    """
    Load sequence from file in FASTA file_format
    filename - Path and filename of input sequence file
    """
    content = None
    try:
        content = SeqIO.read(filename, file_format, IUPAC.unambiguous_dna)
    except ValueError as e:
        print('ERROR: {}'.format(e))
        try:
            content = SeqIO.read(filename, file_format, IUPAC.unambiguous_rna)
        except ValueError as e:
            print('ERROR: {}'.format(e))
            exit(1)

    if content:
        seq = content.seq
        return seq
    else:
        return None

@@ -220,27 +220,45 @@
 ile 
-in FASTA file_forma
+and returns sequence as Bio.Seq objec
 t%0A  
@@ -272,9 +272,20 @@
 ame 
--
+   - String;
  Pat
@@ -322,16 +322,128 @@
 ce file%0A
+    file_format - String; Format to be used. Refer to Biopython docs for available formats. Defaults to 'fasta'%0A
     %22%22%22%0A
@@ -462,32 +462,65 @@
 = None%0A    try:%0A
+        # assume sequence is DNA%0A
         content 
@@ -598,32 +598,73 @@
 alueError as e:%0A
+        # if this fails, try RNA instead%0A
         print('E
@@ -824,57 +824,203 @@
     
-print('ERROR: %7B%7D'.format(e))%0A            exit(1)%0A
+# if this fails, too, raise exception and exit with error code 1%0A            print('ERROR: %7B%7D'.format(e))%0A            exit(1)%0A%0A    # if some kind of data could be read, return the sequence object
 %0A   
@@ -1073,24 +1073,47 @@
  return seq%0A
+    # else return None%0A
     else:%0A  

Prepare for tagging release 0.1: Add comments to LibCharm.IO