Create K’th Non-repeating Character in Python using List Comprehension and OrderedDict

Author: Ank-1234

K’th Non-repeating Character in Python using List Comprehension and OrderedDict

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+def kthRepeating(input,k):
+ 
+    # OrderedDict returns a dictionary data
+        # structure having characters of input
+    # string as keys in the same order they
+        # were inserted and 0 as their default value
+    dict=OrderedDict.fromkeys(input,0)
+ 
+    # now traverse input string to calculate
+        # frequency of each character
+    for ch in input:
+        dict[ch]+=1
+ 
+    # now extract list of all keys whose value
+        # is 1 from dict Ordered Dictionary
+    nonRepeatDict = [key for (key,value) in dict.items() if value==1]
+     
+    # now return (k-1)th character from above list
+    if len(nonRepeatDict) < k:
+        return 'Less than k non-repeating characters in input.'
+    else:
+        return nonRepeatDict[k-1]
+ 
+# Driver function
+if __name__ == "__main__":
+    input = "Ankur Ranjan"
+    k = 3
+    print (kthRepeating(input, k))