<p>You can do this directly on UniProt: <a href="https://www.uniprot.org/uploadlists/" rel="nofollow noreferrer">https://www.uniprot.org/uploadlists/</a></p>
<p>Just paste or upload your list of UniProt IDs, and select &quot;UniProtKB AC/ID&quot; in the &quot;From&quot; field and &quot;UniParc&quot; in the &quot;To&quot; field</p>
<p><a href="https://i.sstatic.net/Wu1o0.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Wu1o0.png" alt="screenshot of the relevant Uniprot.org page" /></a></p>
<hr />
<p>I've also written a script, pasted below, that can do this with some useful options:</p>
<pre class="lang-none prettyprint-override"><code>$ uniprot_map.pl -h

uniprot_map.pl will connect to UniProt and map IDs from the input file to ehatever ID was requested.

USAGE:
       uniprot_map.pl [options] &lt;ID_LIST&gt;

OPTIONS:
      -h : Print this help and exit.
      -f : From ID type. This is the type of ID found in the input file.
      -F : Format. See http://www.uniprot.org/faq/28#batch_retrieval_of_entries for details. 

      -l : When a requested ID maps to many output IDs, print only the first (probably the best) match.
      -L : List all recognised ID types.
      -u : Print unreviewed (trEMBL) prots as well. By default, if an ID maps to SWISSPROT and trEMBL IDs 
           only the SWISSPROTs will be printed, use this flag to print trEMBL as well.
      -t : To ID. This is the ID type that the input IDs will be mapped to.
      -v : Verbose. Print progress messages to STDERR.
</code></pre>
<p>If you save the script as <code>uniprot_map.pl</code> in a directory in your PATH and make it executable, then you can use a file like this:</p>
<pre><code>$ cat file
P31946
P62258
</code></pre>
<p>And feed it to the script with the appropriate options to get the mapping:</p>
<pre class="lang-perl prettyprint-override"><code>$ uniprot_map.pl -f ID -t UniParc file
P31946  UPI000013C714
P62258  UPI0000021A46
2 of 2
</code></pre>
<p>The script:</p>
<pre class="lang-perl prettyprint-override"><code>#!/usr/bin/perl
use strict;
use warnings;
use LWP::UserAgent;
use Getopt::Std;
my %opts;
getopts('Lsvuhf:F:t:l', \%opts);
my <span class="math-container">$base = 'http://www.uniprot.org';
my $</span>verbose=<span class="math-container">$opts{v}||undef;
my $</span>tool = 'mapping';
my (@NAMES,@names);
my <span class="math-container">$print_only_first=$</span>opts{l}||undef;
my <span class="math-container">$allow_trembl=$</span>opts{u}||undef;
list_ids() if <span class="math-container">$opts{L};
&amp;usage() if $</span>opts{h};

&amp;usage() unless $ARGV[0];

####################################
# Collect the IDs we want to match #
####################################
foreach my <span class="math-container">$ar(@ARGV){
if (-e $ar){
open(A, $ar);
while(&lt;A&gt;){
    chomp;
    push @names,$_;
}
}
else{push @names,$</span>ar};
}

######################################
# What are we matching FROM and TO ? #
######################################
my <span class="math-container">$from=$</span>opts{f}||'ID';
my <span class="math-container">$to = $</span>opts{t}||'ACC';

if(<span class="math-container">$opts{t}){
$to=translate_terms($to);
}
if($</span>opts{f}){
    <span class="math-container">$from=translate_terms($</span>from);
}
#################
# Output format #
#################
my <span class="math-container">$format = $</span>opts{F}||'tab';
#my @query=


my <span class="math-container">$agent = LWP::UserAgent-&gt;new;
push @{$</span>agent-&gt;requests_redirectable}, 'POST';

my <span class="math-container">$params= {
'from' =&gt; $from,
'to' =&gt; $to,
'format' =&gt; $</span>format,
    'query' =&gt; &quot;@names&quot;
};

print STDERR &quot;Requesting...\t&quot; if <span class="math-container">$verbose;
my $</span>try_again=1;
my <span class="math-container">$response;
while($</span>try_again==1){
    <span class="math-container">$response = get_response($</span>params);
    if(defined(<span class="math-container">$response-&gt;is_success)){$try_again=0}
elsif($</span>verbose){print STDERR &quot;Failed, retrying...\n&quot;; }
}

if( <span class="math-container">$print_only_first) 
{
if($response-&gt;is_success){
my %k;
my @a=split(/\n/,$response-&gt;content);
foreach my $line(@a){
    next if $line=~/From/;
    my @b=split(/\t/,$line);
    next if(defined($k{$b[0]}));
    $k{$b[0]}=$b[1];
}
map{print STDOUT "$_\t$k{$_}\n"}keys(%k);
}
else{
die 'Failed, got ' . $response-&gt;status_line . ' for ' . $response-&gt;request-&gt;uri . "\n";
}
}
else{
if($response-&gt;is_success){ 
my %map;
my @a=split(/\n/,$response-&gt;content);
#############################
    # remove "From   To"   line #
    #############################
shift(@a) if $a[0] =~/^From/i;
my %kk;
map{
    ########################################################
        # UniProt sometimes returns the SAME line twice    #
        ########################################################
    $kk{$_}++;
    #print STDOUT "$_\n" unless $kk{$_}&gt;1; 
    next if $kk{$_}&gt;1; 
    my @b=split(/\t/);
    push @{$map{$b[0]}},$</span>b[1];
    }@a;

    foreach my <span class="math-container">$query (keys(%map)) {
    my %sw;
    foreach my $target (@{$map{$query}}) {
    #############################################
            # Does this prot have SWISSPROT IDs?        #
            #############################################
    if ($to eq 'ID')
    {
        my @b=split(/_/,$target);
        $sw{$target}++ if length($b[0])!=6;
    }
    }
    foreach my $target (@{$map{$query}}) {
    ################################################
    # If a protein has a least one SWISSPROT ID    #
    # skip printing its trEMBL ones unless -u      #
    ################################################
    if ($to eq 'ID' and not $allow_trembl and scalar(keys(%sw)) &gt; 0) {
        print "$query\t$target\n" if defined($sw{$target});
    }
    else {
        print "$query\t$</span>target\n&quot;;
        }
        }
    }
    
    ## Count how many were actually found
    my %found;
    foreach my <span class="math-container">$resp (@a){
    #print STDERR "R:$resp\t";
    foreach my $id (@names){
    #print STDERR "I:$id\n";
    $found{$id}++ if $resp=~/^$</span>id\t/;
        }
        
    }
    print STDERR scalar(keys(%found)) . &quot; of &quot; . scalar @names . &quot;\n&quot;;

    }
    else{
        die 'Failed, got ' . <span class="math-container">$response-&gt;status_line . 
    ' for ' . $</span>response-&gt;request-&gt;uri . &quot;\n&quot;;
    }
}
################################################
# This will translate <span class="math-container">$to and $</span>from values     #
# between the names used in uniprot flat files #
# and those used by the uniprot database       #
################################################
sub translate_terms{
    my <span class="math-container">$id=shift();
my %hash=(
"AC" =&gt; "ACC", "ID" =&gt; "ID", "UniParc" =&gt; "UPARC", "UniRef50" =&gt; "NF50", "UniRef90" =&gt; "NF90", "UniRef100" =&gt; "NF100", "EMBL/GenBank/DDBJ" =&gt; "EMBL_ID", "EMBL/GenBank/DDBJ CDS" =&gt; "EMBLD", "PIR" =&gt; "PIR", "UniGene" =&gt; "UNIGENE_ID", "GI number*" =&gt; "P_GI", "IPI" =&gt; "P_IPI", "RefSeq" =&gt; "P_REFSEQ_AC", "PDB" =&gt; "PDB_ID", "DisProt" =&gt; "DISPROT_ID", "HSSP" =&gt; "HSSP_ID", "DIP" =&gt; "DIP_ID", "MINT" =&gt; "MINT_ID", "MEROPS" =&gt; "MEROPS_ID", "PeroxiBase" =&gt; "PEROXIBASE_ID", "PptaseDB" =&gt; "PPTASEDB_ID", "REBASE" =&gt; "REBASE_ID", "TCDB" =&gt; "TCDB_ID", "Aarhus/Ghent-2DPAGE" =&gt; "AARHUS_GHENT_2DPAGE_ID", "ECO2DBASE" =&gt; "ECO2DBASE_ID", "World-2DPAGE" =&gt; "WORLD_2DPAGE_ID", "Ensembl" =&gt; "ENSEMBL_ID", "Ensembl Protein" =&gt; "ENSEMBL_PRO_ID", "Ensembl  Trscrpt" =&gt; "ENSEMBL_TRS_ID", "Ensembl  Genomes" =&gt; "ENSEMBLGENOME_ID", "Ensembl    Genomes" =&gt; "Protein", "Ensembl Genomes" =&gt; "Transcript", "GeneID" =&gt; "P_ENTREZGENEID", "GenomeReviews" =&gt; "GENOMEREVIEWS_ID", "KEGG" =&gt; "KEGG_ID", "TIGR" =&gt; "TIGR_ID", "UCSC" =&gt; "UCSC_ID", "VectorBase" =&gt; "VECTORBASE_ID", "AGD" =&gt; "AGD_ID", "ArachnoServer" =&gt; "ARACHNOSERVER_ID", "CGD" =&gt; "CGD", "ConoServer" =&gt; "CONOSERVER_ID", "CYGD" =&gt; "CYGD_ID", "dictyBase" =&gt; "DICTYBASE_ID", "EchoBASE" =&gt; "ECHOBASE_ID", "EcoGene" =&gt; "ECOGENE_ID", "euHCVdb" =&gt; "EUHCVDB_ID", "EuPathDB" =&gt; "EUPATHDB_ID", "FlyBase" =&gt; "FLYBASE_ID", "GeneCards" =&gt; "GENECARDS_ID", "GeneDB_Spombe" =&gt; "GENEDB_SPOMBE_ID", "GeneFarm" =&gt; "GENEFARM_ID", "GenoList" =&gt; "GENOLIST_ID", "H-InvDB" =&gt; "H_INVDB_ID", "HGNC" =&gt; "HGNC_ID", "HPA" =&gt; "HPA_ID", "LegioList" =&gt; "LEGIOLIST_ID", "Leproma" =&gt; "LEPROMA_ID", "MaizeGDB" =&gt; "MAIZEGDB_ID", "MIM" =&gt; "MIM_ID", "MGI" =&gt; "MGI_ID", "NMPDR" =&gt; "NMPDR", "Orphanet" =&gt; "ORPHANET_ID", "PharmGKB" =&gt; "PHARMGKB_ID", "PseudoCAP" =&gt; "PSEUDOCAP_ID", "RGD" =&gt; "RGD_ID", "SGD" =&gt; "SGD_ID", "TAIR" =&gt; "TAIR_ID", "TubercuList" =&gt; "TUBERCULIST_ID", "WormBase" =&gt; "WORMBASE_ID", "WormBase Trscrpt" =&gt; "WORMBASE_TRS_ID", "WormBase Protein" =&gt; "WORMBASE_PRO_ID", "Xenbase" =&gt; "XENBASE_ID", "ZFIN" =&gt; "ZFIN_ID", "eggNOG" =&gt; "EGGNOG_ID", "HOGENOM" =&gt; "HOGENOM_ID", "HOVERGEN" =&gt; "HOVERGEN_ID", "OMA" =&gt; "OMA_ID", "OrthoDB" =&gt; "ORTHODB_ID", "ProtClustDB" =&gt; "PROTCLUSTDB_ID", "BioCyc" =&gt; "BIOCYC_ID", "Reactome" =&gt; "REACTOME_ID", "CleanEx" =&gt; "CLEANEX_ID", "GermOnline" =&gt; "GERMONLINE_ID", "DrugBank" =&gt; "DRUGBANK_ID", "NextBio" =&gt; "NEXTBIO_ID"
);
defined($</span>hash{<span class="math-container">$id}) ? 
return($</span>hash{<span class="math-container">$id}) : 
return($</span>id) ;
}

sub get_response{
    my <span class="math-container">$params=shift;
my $</span>response = <span class="math-container">$agent-&gt;post("$</span>base/<span class="math-container">$tool/", $</span>params);
    while (my <span class="math-container">$wait = $</span>response-&gt;header('Retry-After')) {
    print STDERR &quot;Waiting (<span class="math-container">$wait)...\n";
sleep $</span>wait;
    <span class="math-container">$response = $</span>agent-&gt;get(<span class="math-container">$response-&gt;base);
}
return($</span>response);

}





sub usage{
    <span class="math-container">$0=~s/.+?([^\/]+)$</span>/$1/;


    print STDERR &lt;&lt;EndOfHelp;

$0 will connect to UniProt and map IDs from the input file to ehatever ID was requested.

USAGE:
       $0 [options] &lt;ID_LIST&gt;

OPTIONS:
      -h : Print this help and exit.
      -f : From ID type. This is the type of ID found in the input file.
      -F : Format. See http://www.uniprot.org/faq/28#batch_retrieval_of_entries for details. 

      -l : When a requested ID maps to many output IDs, print only the first (probably the best) match.
      -L : List all recognised ID types.
      -u : Print unreviewed (trEMBL) prots as well. By default, if an ID maps to SWISSPROT and trEMBL IDs 
           only the SWISSPROTs will be printed, use this flag to print trEMBL as well.
      -t : To ID. This is the ID type that the input IDs will be mapped to.
      -v : Verbose. Print progress messages to STDERR.
EndOfHelp

    exit(0);

}
sub list_ids{
    open(HELP, &quot;| less&quot;) ;
    print HELP &lt;&lt;EndOfHelp;

Database            Abbreviation
===================== UniProt =============================
UniProtKB AC/ID :   ACC+ID
UniProtKB AC    :   ACC
UniProtKB ID    :   ID
UniParc         :   UPARC
UniRef50    :   NF50
UniRef90    :   NF90
UniRef100   :   NF100

=============== Other sequence databases ==================
EMBL/GenBank/DDBJ:  EMBL_ID
EMBL/GenBank/DDBJ CDS:  EMBLD
PIR     :   PIR
UniGene     :   UNIGENE_ID
GI number*  :   P_GI
IPI     :   P_IPI
RefSeq      :   P_REFSEQ_AC
HGNC name       :       GENENAME
================== 3D structure databases =================
PDB     :   PDB_ID
DisProt     :   DISPROT_ID
HSSP        :   HSSP_ID

============ Protein-protein interaction databases ========
DIP     :   DIP_ID
MINT        :   MINT_ID

============ Protein family/group databases ===============
MEROPS      :   MEROPS_ID
PeroxiBase  :   PEROXIBASE_ID
PptaseDB    :   PPTASEDB_ID
REBASE      :   REBASE_ID
TCDB        :   TCDB_ID

================== 2D gel databases =======================
Aarhus/Ghent-2DPAGE:  AARHUS_GHENT_2DPAGE_ID
ECO2DBASE   :   ECO2DBASE_ID
World-2DPAGE    :   WORLD_2DPAGE_ID

============= Genome annotation databases =================
Ensembl         :   ENSEMBL_ID
Ensembl Protein :   ENSEMBL_PRO_ID
Ensembl Trscrpt :   ENSEMBL_TRS_ID
Ensembl Genomes :   ENSEMBLGENOME_ID
Ensembl Genomes :   Protein
Ensembl Genomes :   Transcript
GeneID          :   P_ENTREZGENEID
GenomeReviews   :   GENOMEREVIEWS_ID
KEGG        :   KEGG_ID 
TIGR        :   TIGR_ID 
UCSC        :   UCSC_ID 
VectorBase  :   VECTORBASE_ID

============ Organism-specific gene databases =============
AGD     :   AGD_ID  
ArachnoServer   :   ARACHNOSERVER_ID
CGD     :   CGD 
ConoServer  :   CONOSERVER_ID
CYGD        :   CYGD_ID 
dictyBase   :   DICTYBASE_ID
EchoBASE    :   ECHOBASE_ID
EcoGene     :   ECOGENE_ID
euHCVdb     :   EUHCVDB_ID
EuPathDB    :   EUPATHDB_ID
FlyBase     :   FLYBASE_ID
GeneCards   :   GENECARDS_ID
GeneDB_Spombe   :   GENEDB_SPOMBE_ID
GeneFarm    :   GENEFARM_ID
GenoList    :   GENOLIST_ID
H-InvDB     :   H_INVDB_ID
HGNC        :   HGNC_ID 
HPA     :   HPA_ID  
LegioList   :   LEGIOLIST_ID
Leproma     :   LEPROMA_ID
MaizeGDB    :   MAIZEGDB_ID
MIM     :   MIM_ID  
MGI     :   MGI_ID  
NMPDR       :   NMPDR   
Orphanet    :   ORPHANET_ID
PharmGKB    :   PHARMGKB_ID
PseudoCAP   :   PSEUDOCAP_ID
RGD     :   RGD_ID  
SGD     :   SGD_ID  
TAIR        :   TAIR_ID 
TubercuList :   TUBERCULIST_ID
WormBase    :   WORMBASE_ID
WormBase Trscrpt:   WORMBASE_TRS_ID
WormBase Protein:   WORMBASE_PRO_ID
Xenbase     :   XENBASE_ID
ZFIN        :   ZFIN_ID

================= Phylogenomic databases ==================
eggNOG      :   EGGNOG_ID
HOGENOM     :   HOGENOM_ID
HOVERGEN    :   HOVERGEN_ID
OMA     :   OMA_ID
OrthoDB     :   ORTHODB_ID
ProtClustDB :   PROTCLUSTDB_ID

=================== Enzyme and pathway ====================
BioCyc      :   BIOCYC_ID
Reactome    :   REACTOME_ID

================= Gene expression databases ===============
CleanEx     :   CLEANEX_ID
GermOnline  :   GERMONLINE_ID

========================== Other ==========================
DrugBank    :   DRUGBANK_ID
NextBio     :   NEXTBIO_ID

EndOfHelp
close(HELP);
    exit(0);
}
</code></pre>
<p>If you have too many IDs to do in a single batch, you could either simply split the file into smaller ones and run the script on each file in a loop or modify the script to do it.</p>
<p>Split the input:</p>
<pre class="lang-sh prettyprint-override"><code>$ wc -l names
$ wc -l names
500000 names
## split into 500 files of 1K lines each
$ split -l 1000 names chunk
## iterate over each chunk of names
$ for i in chunk*; do uniprot_map.pl -f ID -t UniParc &quot;$i&quot; &gt;&gt; mapped; done
</code></pre>

CC BY-SA 4.0
2022-03-05T00:52:13.937Z
Thank you @terdon for the detailed answer and your script! Let me try it out!
Johnny Tam
CC BY-SA 4.0
2022-03-05T01:05:09.177Z
Seems both of the solutions require ID list < 2Mb. I will try to look into the XML file of UniProt. Please check out: https://blog.liang2.tw/posts/2018/01/read-uniprotkb-xml/
Johnny Tam
CC BY-SA 4.0
2022-03-05T09:36:16.430Z
@JohnnyTam just split your file and run the script in a loop. Or change the script to run them in batches.
terdon
CC BY-SA 4.0
2022-03-05T10:24:57.250Z
@JohnnyTam see updated answer for how to split the input. Alternatively, if you can give me your list of names, I can have a go at modifying the script to handle them.
terdon
CC BY-SA 4.0
2022-03-08T07:30:27.237Z
Ops, I forgot I can split. It worked perfectly! Thank you very much!
Johnny Tam
CC BY-SA 4.0
2022-03-04T12:13:03.623Z
2022-03-05T10:24:27.867Z
2022-03-05T10:24:27.867Z
terdon
<p>I want to map ~500,000 UniProt IDs to their representative UniRef90 IDs.</p>
<p>What is the most efficient way of doing this?</p>
<p>Do we have a table with the mapping?</p>

<uniprot>
Efficient way of mapping UniProt IDs to representative UniRef90 IDs?
# Efficient way of mapping UniProt IDs to representative UniRef90 IDs?

(Asked by: username_0 on 2022-03-04)

I want to map ~500,000 UniProt IDs to their representative UniRef90 IDs.

What is the most efficient way of doing this?

Do we have a table with the mapping?

**Tags:** uniprot

---

## 1 answers

### Answer by username_1 on 2022-03-04. Score: 2 | Accepted answer

You can do this directly on UniProt: https://www.uniprot.org/uploadlists/
Just paste or upload your list of UniProt IDs, and select "UniProtKB AC/ID" in the "From" field and "UniParc" in the "To" field


I've also written a script, pasted below, that can do this with some useful options:
$ uniprot_map.pl -h

uniprot_map.pl will connect to UniProt and map IDs from the input file to ehatever ID was requested.

USAGE:
       uniprot_map.pl [options] 

OPTIONS:
      -h : Print this help and exit.
      -f : From ID type. This is the type of ID found in the input file.
      -F : Format. See http://www.uniprot.org/faq/28#batch_retrieval_of_entries for details. 

      -l : When a requested ID maps to many output IDs, print only the first (probably the best) match.
      -L : List all recognised ID types.
      -u : Print unreviewed (trEMBL) prots as well. By default, if an ID maps to SWISSPROT and trEMBL IDs 
           only the SWISSPROTs will be printed, use this flag to print trEMBL as well.
      -t : To ID. This is the ID type that the input IDs will be mapped to.
      -v : Verbose. Print progress messages to STDERR.

If you save the script as uniprot_map.pl in a directory in your PATH and make it executable, then you can use a file like this:
$ cat file
P31946
P62258

And feed it to the script with the appropriate options to get the mapping:
$ uniprot_map.pl -f ID -t UniParc file
P31946  UPI000013C714
P62258  UPI0000021A46
2 of 2

The script:
#!/usr/bin/perl
use strict;
use warnings;
use LWP::UserAgent;
use Getopt::Std;
my %opts;
getopts('Lsvuhf:F:t:l', \%opts);
my $base = 'http://www.uniprot.org';
my $verbose=$opts{v}||undef;
my $tool = 'mapping';
my (@NAMES,@names);
my $print_only_first=$opts{l}||undef;
my $allow_trembl=$opts{u}||undef;
list_ids() if $opts{L};
&usage() if $opts{h};

&usage() unless $ARGV[0];

####################################
# Collect the IDs we want to match #
####################################
foreach my $ar(@ARGV){
if (-e $ar){
open(A, $ar);
while(){
    chomp;
    push @names,$_;
}
}
else{push @names,$ar};
}

######################################
# What are we matching FROM and TO ? #
######################################
my $from=$opts{f}||'ID';
my $to = $opts{t}||'ACC';

if($opts{t}){
$to=translate_terms($to);
}
if($opts{f}){
    $from=translate_terms($from);
}
#################
# Output format #
#################
my $format = $opts{F}||'tab';
#my @query=


my $agent = LWP::UserAgent->new;
push @{$agent->requests_redirectable}, 'POST';

my $params= {
'from' => $from,
'to' => $to,
'format' => $format,
    'query' => "@names"
};

print STDERR "Requesting...\t" if $verbose;
my $try_again=1;
my $response;
while($try_again==1){
    $response = get_response($params);
    if(defined($response->is_success)){$try_again=0}
elsif($verbose){print STDERR "Failed, retrying...\n"; }
}

if( $print_only_first) 
{
if($response->is_success){
my %k;
my @a=split(/\n/,$response->content);
foreach my $line(@a){
    next if $line=~/From/;
    my @b=split(/\t/,$line);
    next if(defined($k{$b[0]}));
    $k{$b[0]}=$b[1];
}
map{print STDOUT "$_\t$k{$_}\n"}keys(%k);
}
else{
die 'Failed, got ' . $response->status_line . ' for ' . $response->request->uri . "\n";
}
}
else{
if($response->is_success){ 
my %map;
my @a=split(/\n/,$response->content);
#############################
    # remove "From   To"   line #
    #############################
shift(@a) if $a[0] =~/^From/i;
my %kk;
map{
    ########################################################
        # UniProt sometimes returns the SAME line twice    #
        ########################################################
    $kk{$_}++;
    #print STDOUT "$_\n" unless $kk{$_}>1; 
    next if $kk{$_}>1; 
    my @b=split(/\t/);
    push @{$map{$b[0]}},$b[1];
    }@a;

    foreach my $query (keys(%map)) {
    my %sw;
    foreach my $target (@{$map{$query}}) {
    #############################################
            # Does this prot have SWISSPROT IDs?        #
            #############################################
    if ($to eq 'ID')
    {
        my @b=split(/_/,$target);
        $sw{$target}++ if length($b[0])!=6;
    }
    }
    foreach my $target (@{$map{$query}}) {
    ################################################
    # If a protein has a least one SWISSPROT ID    #
    # skip printing its trEMBL ones unless -u      #
    ################################################
    if ($to eq 'ID' and not $allow_trembl and scalar(keys(%sw)) > 0) {
        print "$query\t$target\n" if defined($sw{$target});
    }
    else {
        print "$query\t$target\n";
        }
        }
    }
    
    ## Count how many were actually found
    my %found;
    foreach my $resp (@a){
    #print STDERR "R:$resp\t";
    foreach my $id (@names){
    #print STDERR "I:$id\n";
    $found{$id}++ if $resp=~/^$id\t/;
        }
        
    }
    print STDERR scalar(keys(%found)) . " of " . scalar @names . "\n";

    }
    else{
        die 'Failed, got ' . $response->status_line . 
    ' for ' . $response->request->uri . "\n";
    }
}
################################################
# This will translate $to and $from values     #
# between the names used in uniprot flat files #
# and those used by the uniprot database       #
################################################
sub translate_terms{
    my $id=shift();
my %hash=(
"AC" => "ACC", "ID" => "ID", "UniParc" => "UPARC", "UniRef50" => "NF50", "UniRef90" => "NF90", "UniRef100" => "NF100", "EMBL/GenBank/DDBJ" => "EMBL_ID", "EMBL/GenBank/DDBJ CDS" => "EMBLD", "PIR" => "PIR", "UniGene" => "UNIGENE_ID", "GI number*" => "P_GI", "IPI" => "P_IPI", "RefSeq" => "P_REFSEQ_AC", "PDB" => "PDB_ID", "DisProt" => "DISPROT_ID", "HSSP" => "HSSP_ID", "DIP" => "DIP_ID", "MINT" => "MINT_ID", "MEROPS" => "MEROPS_ID", "PeroxiBase" => "PEROXIBASE_ID", "PptaseDB" => "PPTASEDB_ID", "REBASE" => "REBASE_ID", "TCDB" => "TCDB_ID", "Aarhus/Ghent-2DPAGE" => "AARHUS_GHENT_2DPAGE_ID", "ECO2DBASE" => "ECO2DBASE_ID", "World-2DPAGE" => "WORLD_2DPAGE_ID", "Ensembl" => "ENSEMBL_ID", "Ensembl Protein" => "ENSEMBL_PRO_ID", "Ensembl  Trscrpt" => "ENSEMBL_TRS_ID", "Ensembl  Genomes" => "ENSEMBLGENOME_ID", "Ensembl    Genomes" => "Protein", "Ensembl Genomes" => "Transcript", "GeneID" => "P_ENTREZGENEID", "GenomeReviews" => "GENOMEREVIEWS_ID", "KEGG" => "KEGG_ID", "TIGR" => "TIGR_ID", "UCSC" => "UCSC_ID", "VectorBase" => "VECTORBASE_ID", "AGD" => "AGD_ID", "ArachnoServer" => "ARACHNOSERVER_ID", "CGD" => "CGD", "ConoServer" => "CONOSERVER_ID", "CYGD" => "CYGD_ID", "dictyBase" => "DICTYBASE_ID", "EchoBASE" => "ECHOBASE_ID", "EcoGene" => "ECOGENE_ID", "euHCVdb" => "EUHCVDB_ID", "EuPathDB" => "EUPATHDB_ID", "FlyBase" => "FLYBASE_ID", "GeneCards" => "GENECARDS_ID", "GeneDB_Spombe" => "GENEDB_SPOMBE_ID", "GeneFarm" => "GENEFARM_ID", "GenoList" => "GENOLIST_ID", "H-InvDB" => "H_INVDB_ID", "HGNC" => "HGNC_ID", "HPA" => "HPA_ID", "LegioList" => "LEGIOLIST_ID", "Leproma" => "LEPROMA_ID", "MaizeGDB" => "MAIZEGDB_ID", "MIM" => "MIM_ID", "MGI" => "MGI_ID", "NMPDR" => "NMPDR", "Orphanet" => "ORPHANET_ID", "PharmGKB" => "PHARMGKB_ID", "PseudoCAP" => "PSEUDOCAP_ID", "RGD" => "RGD_ID", "SGD" => "SGD_ID", "TAIR" => "TAIR_ID", "TubercuList" => "TUBERCULIST_ID", "WormBase" => "WORMBASE_ID", "WormBase Trscrpt" => "WORMBASE_TRS_ID", "WormBase Protein" => "WORMBASE_PRO_ID", "Xenbase" => "XENBASE_ID", "ZFIN" => "ZFIN_ID", "eggNOG" => "EGGNOG_ID", "HOGENOM" => "HOGENOM_ID", "HOVERGEN" => "HOVERGEN_ID", "OMA" => "OMA_ID", "OrthoDB" => "ORTHODB_ID", "ProtClustDB" => "PROTCLUSTDB_ID", "BioCyc" => "BIOCYC_ID", "Reactome" => "REACTOME_ID", "CleanEx" => "CLEANEX_ID", "GermOnline" => "GERMONLINE_ID", "DrugBank" => "DRUGBANK_ID", "NextBio" => "NEXTBIO_ID"
);
defined($hash{$id}) ? 
return($hash{$id}) : 
return($id) ;
}

sub get_response{
    my $params=shift;
my $response = $agent->post("$base/$tool/", $params);
    while (my $wait = $response->header('Retry-After')) {
    print STDERR "Waiting ($wait)...\n";
sleep $wait;
    $response = $agent->get($response->base);
}
return($response);

}





sub usage{
    $0=~s/.+?([^\/]+)$/$1/;


    print STDERR <

OPTIONS:
      -h : Print this help and exit.
      -f : From ID type. This is the type of ID found in the input file.
      -F : Format. See http://www.uniprot.org/faq/28#batch_retrieval_of_entries for details. 

      -l : When a requested ID maps to many output IDs, print only the first (probably the best) match.
      -L : List all recognised ID types.
      -u : Print unreviewed (trEMBL) prots as well. By default, if an ID maps to SWISSPROT and trEMBL IDs 
           only the SWISSPROTs will be printed, use this flag to print trEMBL as well.
      -t : To ID. This is the ID type that the input IDs will be mapped to.
      -v : Verbose. Print progress messages to STDERR.
EndOfHelp

    exit(0);

}
sub list_ids{
    open(HELP, "| less") ;
    print HELP <
If you have too many IDs to do in a single batch, you could either simply split the file into smaller ones and run the script on each file in a loop or modify the script to do it.
Split the input:
$ wc -l names
$ wc -l names
500000 names
## split into 500 files of 1K lines each
$ split -l 1000 names chunk
## iterate over each chunk of names
$ for i in chunk*; do uniprot_map.pl -f ID -t UniParc "$i" >> mapped; done

> **Comments:**
> **username_0**: Thank you @terdon for the detailed answer and your script! Let me try it out!  
> **username_0**: Seems both of the solutions require ID list < 2Mb. I will try to look into the XML file of UniProt. Please check out: https://blog.liang2.tw/posts/2018/01/read-uniprotkb-xml/  
> **username_1**: @JohnnyTam just split your file and run the script in a loop. Or change the script to run them in batches.  
> **username_1**: @JohnnyTam see updated answer for how to split the input. Alternatively, if you can give me your list of names, I can have a go at modifying the script to handle them.  
> **username_0**: Ops, I forgot I can split. It worked perfectly! Thank you very much!  

---

