In [17]: lst = [5, "Paul", 4, 2, "Mary", 1, "Dick", "Zoe", 3]
In [18]: min_num = min( i for i in lst if isinstance(i, int) )
 
In [19]: min_str = min( i for i in lst if isinstance(i, str) )
 
In [20]: min_num
Out[20]: 1
 
In [21]: min_str
Out[21]: 'Dick'

lst = [11, 'Dick', 12, 'Mary', 7, 'Zoe', 9, 700, 777, 'Paul', 13456789]
slist = sorted(lst) #sort the list
min_num , max_str = slist[0],  slist[-1]  #first and last element usually is minnum, max str.
for num,item in enumerate(slist):
  try:
    if item.isalpha():  #check for first occurence of a word.
      min_str = item
      max_num = slist[num-1]  #get the number on the left of this word. Usually is max num
      break
  except: pass
print min_num ,max_num , max_str ,  min_str

# convert all list items to type string ...
mixed_list = [11, 'Dick', 12, 'Mary', 7, 'Zoe', 9, 700, 777, 'Paul', 13456789]
str_list = [str(x) for x in mixed_list]
# now it's a pure ASCII sort ...
print sorted(str_list)
"""
output -->
['11', '12', '13456789', '7', '700', '777', '9', 'Dick', 'Mary', 'Paul', 'Zoe']
"""

def minmax4(lst, typ):
    """return min/max of mixed list lst for items of type typ"""
    temp = [x for x in lst if isinstance(x, typ)]
    return min(temp), max(temp)
 
# minmax4() test ...
mixed_list = [11, 'Dick', 12, 'Mary', 7, 'Zoe', 9, 700, 777, 'Paul', 13456789]
print mixed_list
 
print "The min and max of the integers are:"
mn, mx = minmax4(mixed_list, int)
print "minimum = %s  maximum = %s" % (mn, mx)
 
print "The min and max of the strings are:"
mn, mx = minmax4(mixed_list, str)
print "minimum = %s  maximum = %s" % (mn, mx)
"""
minmax4() test output -->
[11, 'Dick', 12, 'Mary', 7, 'Zoe', 9, 700, 777, 'Paul', 13456789]
The min and max of the integers are:
minimum = 7  maximum = 13456789
The min and max of the strings are:
minimum = Dick  maximum = Zoe
"""