Find the most common n-grams in an input string

ngrams.py

# Adapted from this SO post https://stackoverflow.com/a/14670769/1229735

from collections import Counter

counter = Counter()
text = '' # Put your text here. It helps to prune stuff from the input that you consider noise.

min_substring_length = 7
max_substring_length = 15 # len(text) + 1 # for max length

def firstCharacterIsUpper(input):
    return input[:1].isupper()

def upperCaseLimit(input, min, max):
    count = 0
    for char in input:
        if (char.isupper()):
            count += 1
    return min <= count and count <= max

def containsNoSpaces(input):
    return ' ' not in input

# end = rom min_substring_length to end
for length in range(min_substring_length, max_substring_length):
    end = len(text) - length
    # start = From 0 to end - length
    for start in range(end):
        current_end = start + length
        ngram = text[start:current_end]
        # print("start: {0}, end: {1}, ngram: {2}".format(start, current_end, ngram))
        # if (firstCharacterIsUpper(ngram) and containsNoSpaces(ngram) and upperCaseLimit(ngram, 1, 2)):
        counter[ngram] += 1

print(Counter(counter).most_common(100))