Only in a: currency.units
diff -ru a/units_cur b/units_cur
--- a/units_cur	2018-09-15 16:30:09.000000000 -0400
+++ b/units_cur	2021-07-11 18:01:29.030260473 -0400
@@ -28,8 +28,12 @@
 #
 #
 
-version = '5.0'
+version = '5.1'
 
+# Version 5.1:
+#
+# Switch to urllib to avoid requests dependency.
+#
 # Version 5.0:
 #
 # Rewrite to support multiple different data sources due to disappearance
@@ -54,8 +58,11 @@
 # Python 2 or Python 3.  Thanks to Ray Hamel for some help with this update.  
 
 # Normal imports
-import requests
 import codecs
+import json
+import urllib.error
+import urllib.parse
+import urllib.request
 from argparse import ArgumentParser
 from collections import OrderedDict
 from datetime import date
@@ -288,11 +295,12 @@
                                                   currency[code][rate_index]))
 
 def getjson(address,args=None):
+  if args:
+    address = address + "?" + urllib.parse.urlencode(args)
   try:
-    res = requests.get(address,args)
-    res.raise_for_status()
-    return(res.json())
-  except requests.exceptions.RequestException as e:
+    res = urllib.request.urlopen(address)
+    return(json.load(res))
+  except urllib.error.URLError as e:
     stderr.write('Error connecting to currency server:\n{}.\n'.format(e))
     exit(1)
         
@@ -323,9 +331,8 @@
     stderr.write('European bank uses euro for base currency.  Specified base {} ignored.\n'.format(base))
   import xml.etree.ElementTree as ET
   try:
-    res=requests.get('https://www.ecb.europa.eu/stats/eurofxref/eurofxref-daily.xml')
-    res.raise_for_status()
-    data = ET.fromstring(res.content)[2][0]
+    res=urllib.request.urlopen('https://www.ecb.europa.eu/stats/eurofxref/eurofxref-daily.xml')
+    data = ET.fromstring(res.read())[2][0]
   except requests.exceptions.RequestException as e:
     stderr.write('Error connecting to currency server:\n{}.\n'.
                  format(e))