When it is required to test for desired string lengths, a simple iteration, and the ‘len’ method is used.ExampleBelow is a demonstration of the same −my_list = ["python", 'is', 'fun', 'to', 'learn', 'Will', 'how'] print("The list is :") print(my_list) length_list = [6, 2, 3, 2, 5, 4, 3] my_result = True for index in range(len(my_list)):    if len(my_list[index]) != length_list[index]:       my_result = False break print("The result is :") if(my_result == True):    print("All the strings are of required lengths") else:    print("All the strings are not of required lengths")OutputThe list is : ... Read More

When it is required to sort a list of strings based on the number of unique characters, a method is defined that uses a ‘set’ operator, the ‘list’ method and the ‘len’ method.ExampleBelow is a demonstration of the same −def my_sort_func(my_elem): return len(list(set(my_elem))) my_list = ['python', "Will", "Hi", "how", 'fun', 'learn', 'code'] print("The list is : ") print(my_list) my_list.sort(key = my_sort_func) print("The result is :") print(my_list)OutputThe list is : ['python', 'Will', 'Hi', 'how', 'fun', 'learn', 'code'] The result is : ['Hi', 'Will', 'how', 'fun', 'code', 'learn', 'python']ExplanationA method named ‘my_sort_func’ is defined, that takes ... Read More

When it is required to extract words starting with vowel from a list, a simple iteration, a flag value and the ‘startswith’ method are used.Below is a demonstration of the same −Example:my_list = ["abc", "phy", "and", "okay", "educate", "learn", "code"] print("The list is :") print(my_list) my_result = [] my_vowel = "aeiou" print("The vowels are ") print(my_vowel) for index in my_list: my_flag = False for element in my_vowel: if index.startswith(element): my_flag = True ... Read More

When it is required to print rows where all its elements’ frequency is greater than K, a method is defined that takes two parameters, and uses ‘all’ operator and iteration to give the result.Below is a demonstration of the same −Exampledef frequency_greater_K(row, K) : return all(row.count(element) > K for element in row) my_list = [[11, 11, 32, 43, 12, 23], [42, 14, 55, 62, 16], [11, 11, 11, 11], [42, 54, 61, 18]] print("The tuple is :") print(my_list) K = 1 print("The value of K is :") print(K) my_result = [row for row in my_list if frequency_greater_K(row, ... Read More

When it is required to repeat elements at custom indices, a simple iteration, enumerate attribute, the ‘extend’ method and the ‘append’ method are used.Below is a demonstration of the same −Examplemy_list = [34, 56, 77, 23, 31, 29, 62, 99] print("The list is :") print(my_list) index_list = [3, 1, 4, 6] my_result = [] for index, element in enumerate(my_list): if index in index_list: my_result.extend([element, element]) else : my_result.append(element) print("The result is :") print(my_result)OutputThe list is : [34, 56, 77, 23, 31, 29, ... Read More

When it is required to find the Fibonacci sequence using the method of recursion, a method named ‘fibonacci_recursion’ is defined, that takes a value as parameter. It is called again and again by reducing the size of the input.Below is a demonstration of the same:Exampledef fibonacci_recursion(my_val): if my_val

When it is required to inverse the dictionary values to a list, a simple iteration and ‘append’ method is used.Below is a demonstration of the same −from collections import defaultdict my_dict = {13: [12, 23], 22: [31], 34: [21], 44: [52, 31]} print("The dictionary is :") print(my_dict) my_result = defaultdict(list) for keys, values in my_dict.items(): for val in values: my_result[val].append(keys) print("The result is :") print(dict(my_result))OutputThe dictionary is : {34: [21], 44: [52, 31], 13: [12, 23], 22: [31]} The result is : {52: [44], 31: [44, 22], 12: [13], 21: [34], ... Read More

When it is required to sort a list of strings based on the ‘K’ number of character frequency, the ‘sorted’ method, and the lambda function is used.ExampleBelow is a demonstration of the same −my_list = ['Hi', 'Will', 'Jack', 'Python', 'Bill', 'Mills', 'goodwill'] print("The list is : " ) print(my_list) my_list.sort() print("The list after sorting is ") print(my_list) K = 'l' print("The value of K is ") print(K) my_result = sorted(my_list, key = lambda ele: -ele.count(K)) print("The resultant list is : ") print(my_result)OutputThe list is : ['Hi', 'Will', 'Jack', 'Python', 'Bill', 'Mills', 'goodwill'] The list after sorting is ... Read More

To groupby columns and count the occurrences of each combination in Pandas, we use the DataFrame.groupby() with size(). The groupby() method separates the DataFrame into groups.At first, let us import the pandas library with an alias pd −import pandas as pdInitialize the data of lists −# initializing the data mylist = {'Car': ['BMW', 'Mercedes', 'Lamborgini', 'Audi', 'Mercedes', 'Porche', 'RollsRoyce', 'BMW'], 'Place': ['Delhi', 'Hyderabad', 'Chandigarh', 'Bangalore', 'Hyderabad', 'Mumbai', 'Mumbai', 'Delhi'], 'Sold': [95, 80, 80, 75, 90, 90, 95, 50 ]}Next, we will create a DataFrame −# DataFrame dataFrame = pd.DataFrame(mylist, columns=['Car', 'Place', 'Sold'])Now, use the groupby() to count the occurrence with ... Read More

When it is required to extracts elements from a list with digits in increasing order, a simple iteration, a flag value and the ‘str’ method is used.Below is a demonstration of the same −Example Live Demomy_list = [4578, 7327, 113, 3467, 1858] print("The list is :") print(my_list) my_result = [] for element in my_list:    my_flag = True    for index in range(len(str(element)) - 1):       if str(element)[index + 1]