use eutils to generate yearly histograms

esearch.sh

esearch -db pubmed -query "Journal of natural products [JOUR] has abstract [FILT]" | \
	efetch -format docsum | \
	xtract -pattern DocumentSummary -element PubDate | \
	cut -d " " -f 1 | \
  cut -d "-" -f 1 | \
	python hist.py --title "J Nat Prod Articles w Abs." --outfile "jnp_abst.png"
	
esearch -db pubmed -query "Journal of natural products [JOUR] " | \
  efilter -query "rifamycin" | \
	efetch -format docsum | \
	xtract -pattern DocumentSummary -element PubDate | \
	cut -d " " -f 1 | \
  cut -d "-" -f 1 | \
	python hist.py --title "J Nat Prod Articles" --outfile "jnp_all.png"
	
esearch -db pubmed -query "CRISPR" | \
	efetch -format docsum | \
	xtract -pattern DocumentSummary -element PubDate | \
	cut -d " " -f 1 | \
  cut -d "-" -f 1 | \
	python hist.py --title "CRISPR" --outfile "eutilsbar_crispr.png"

esearch -db pubmed -query "microbiome" | \
  efetch -format docsum | \
  xtract -pattern DocumentSummary -element PubDate | \
  cut -d " " -f 1 | \
  cut -d "-" -f 1 | \
  python hist.py --title "Microbiome" --outfile "eutilsbar_microbiome.png"

esearch -db pubmed -query "metabolomics" | \
	efetch -format docsum | \
	xtract -pattern DocumentSummary -element PubDate | \
	cut -d " " -f 1 | \
  cut -d "-" -f 1 | \
	python hist.py --title "Metabolomics" --outfile "eutilsbar_metabolomics.png"

esearch -db pubmed -query "rapamycin" | \
	efetch -format docsum | \
	xtract -pattern DocumentSummary -element PubDate | \
	cut -d " " -f 1 | \
  cut -d "-" -f 1 | \
	python hist.py --title "Rapamycin" --outfile "eutilsbar_rapamycin.png"

esearch -db pubmed -query "ebola" | \
	efetch -format docsum | \
	xtract -pattern DocumentSummary -element PubDate | \
	cut -d " " -f 1 | \
  cut -d "-" -f 1 | \
	python hist.py --title "ebola" --outfile "eutilsbar_ebola.png"

esearch -db pubmed -query "tetracycline" | \
	efetch -format docsum | \
	xtract -pattern DocumentSummary -element PubDate | \
	cut -d " " -f 1 | \
  cut -d "-" -f 1 | \
	python hist.py --title "tetracycline" --outfile "eutilsbar_tetracycline.png"

esearch -db pubmed -query "penicillin" | \
	efetch -format docsum | \
	xtract -pattern DocumentSummary -element PubDate | \
	cut -d " " -f 1 | \
  cut -d "-" -f 1 | \
	python hist.py --title "penicillin" --outfile "eutilsbar_penicillin.png"

esearch -db pubmed -query "penicillin" | \
	efetch -format docsum | \
	xtract -pattern DocumentSummary -element PubDate | \
	cut -d " " -f 1 | \
  cut -d "-" -f 1 | \
	python hist.py --title "penicillin" --outfile "eutilsbar_penicillin.png"

esearch -db pubmed -query "tuberculosis" | \
	efetch -format docsum | \
	xtract -pattern DocumentSummary -element PubDate | \
	cut -d " " -f 1 | \
  cut -d "-" -f 1 | \
	python hist.py --title "tuberculosis" --outfile "eutilsbar_tuberculosis.png"

hist.py

import click
import sys
from toolz.itertoolz import frequencies
import matplotlib.pyplot as plt

years = sys.stdin

@click.command()
@click.option('--title', default = "", help='Histrogram Title')
@click.option('--outfile', default = "", help='Histrogram Title')
def process(title, outfile):
    year_freqs = frequencies(years)
    xvals = [int(key.strip()) for key in year_freqs.keys()]
    yvals = [v for v in year_freqs.values()]
    plt.bar(xvals, yvals)
    plt.xlabel('Year')
    plt.ylabel('Frequency')
    plt.title(title)
    plt.savefig(outfile)

if __name__ == "__main__":
    process()