Programming Articles - Page 1064 of 3363

When it is required to find the distance between the first and last even elements of a list, list elements are accessed using indexing and the difference is found.ExampleBelow is a demonstration of the samemy_list = [2, 3, 6, 4, 6, 2, 9, 1, 14, 11] print("The list is :") print(my_list) my_indices_list = [idx for idx in range( len(my_list)) if my_list[idx] % 2 == 0] my_result = my_indices_list[-1] - my_indices_list[0] print("The result is :") print(my_result)OutputThe list is : [2, 3, 6, 4, 6, 2, 9, 1, 14, 11] The result is : 8ExplanationA list ... Read More

When it is required to filter the rows that contains only alphabets in a list of lists, the list is iterated over and the ‘isalpha’ method is used to check if an alphabet is present or not.ExampleBelow is a demonstration of the samemy_list = [["python", "is", "best"], ["abc123", "good"], ["abc def ghij"], ["abc2", "gpqr"]] print("The list is :") print(my_list) my_result = [sub for sub in my_list if all(element.isalpha() for element in sub)] print("The result is :") print(my_result)OutputThe list is : [['python', 'is', 'best'], ['abc123', 'good'], ['abc def ghij'], ['abc2', 'gpqr']] The result is : [['python', 'is', 'best']]ExplanationA list ... Read More

When it is required to find the sum of the length of string at specific indices, the ‘enumerate’ is used to iterate through the elements in the list and adding the length of the element to a list.ExampleBelow is a demonstration of the samemy_list = ["python", "is", "best", "for", "coders"] print("The list is :") print(my_list) index_list = [0, 1, 4] result = 0 for index, element in enumerate(my_list): if index in index_list: result += len(element) print("The result is :") print(result)OutputThe list is : ['python', 'is', 'best', 'for', ... Read More

When it is required to test if the elements are in the min/max range, the list elements are iterated over, and are checked to see if it is equal to ‘max’ value.ExampleBelow is a demonstration of the samemy_list = [5, 6, 4, 7, 8, 13, 15] print("The list is : ") print(my_list) range_list = [4, 7, 10, 6] my_result = True for elem in range_list: if elem!= max(my_list): my_result = False break if(elem == True): print("All the elements are ... Read More

When it is required to find the mean deviation of the elements of a list, the ‘sum’ method and the ‘len’ method is used.ExampleBelow is a demonstration of the samemy_list = [3, 5, 7, 10, 12] print("The list is :") print(my_list) my_mean = sum(my_list) / len(my_list) my_variance = sum([((x – my_mean) ** 2) for x in my_list]) / len(my_list) my_result = my_variance ** 0.5 print("The result is :") print(result)OutputThe original list : [3, 5, 7, 10, 12] the standard deviation of list is : 3.2619012860600183ExplanationA list is defined and is displayed on the console.The ‘sum’ of the ... Read More

To find rolling mean, we will use the apply() function in Pandas. At first, let us import the required library −import pandas as pdCreate a DataFrame with 2 columns. One is an int column −dataFrame = pd.DataFrame(    {       "Car": ['Tesla', 'Mercedes', 'Tesla', 'Mustang', 'Mercedes', 'Mustang'],       "Reg_Price": [5000, 1500, 6500, 8000, 9000, 6000]    } )Group using GroupBy and find the Rolling Mean using apply() −dataFrame.groupby("Car")["Reg_Price"].apply( lambda x: x.rolling(center=False, window=2).mean()) ExampleFollowing is the code −import pandas as pd # Create DataFrame dataFrame = pd.DataFrame( { ... Read More

To delete a column from a DataFrame, use del(). You can also use pop() method to delete. Just drop it using square brackets. Mention the column to be deleted in the brackets and that’s it, for example −del dataFrame[‘ColumnName’]Import the required library with an alias −import pandas as pdCreate a Pandas DataFrame −dataFrame = pd.DataFrame( { "Car": ['BMW', 'Lexus', 'Audi', 'Mustang', 'Bentley', 'Jaguar'], "Units": [100, 150, 110, 80, 110, 90] } ) Now, delete a column “Car” from a DataFrame −del ... Read More

When it is required to sort strings based on case difference, a method is defined that takes a string as a parameter. This method uses list comprehension and ‘isupper’ and ‘islower’ methods along with list comprehension to get case difference. Their difference gives the sorted values.ExampleBelow is a demonstration of the samedef get_diff(my_string):    lower_count = len([ele for ele in my_string if ele.islower()])    upper_count = len([ele for ele in my_string if ele.isupper()])    return abs(lower_count - upper_count) my_list = ["Abc", "Python", "best", "hello", "coders"] print("The list is :") print(my_list) my_list.sort(key=get_diff) print("Sorted Strings by case ... Read More

When it is required to filter similar case strings, list comprehension can be used along with ‘isupper’ and ‘islower’ methods.ExampleBelow is a demonstration of the samemy_list = ["Python", "good", "FOr", "few", "CODERS"] print("The list is :") print(my_list) my_result = [sub for sub in my_list if sub.islower() or sub.isupper()] print("The strings with same case are :") print(my_result)OutputThe list is : ['Python', 'good', 'FOr', 'few', 'CODERS'] The strings with same case are : ['good', 'few', 'CODERS']ExplanationA list is defined and is displayed on the console.The list comprehension is used to iterate over the list and check if the strings ... Read More

When it is required to find the index value that has been repeated in a list, it is iterated over using the list comprehension and ‘enumerate’.ExampleBelow is a demonstration of the samemy_list = [4, 0, 3, 1] print("The list is :") print(my_list) my_result = [element for sub in ([index] * element for index, element in enumerate(my_list)) for element in sub] print("The result is :") print(my_result)OutputThe list is : [4, 0, 3, 1] The result is : [0, 0, 0, 0, 2, 2, 2, 3]ExplanationA list is defined and is displayed on the console.List comprehension is used to ... Read More