Python Articles - Page 358 of 929

Suppose, we are given a string 'input_str'. Now, we are asked to determine every possible substring from the given string then concatenate all the substrings one after another in a lexical order into another string. We are also provided an integer value k. Our task is to return the letter at index k from the concatenated string.So, if the input is like input_str = 'pqrs', k = 6, then the output will be pThe substrings from the given string in lexical order are p, pq, pqr, pqrs, q, qr, qrs, r, rs, s.If we concatenate the strings, it becomes ppqpqrpqrsqqrqrsrrss. ... Read More

To curve text in a polar plot in matplotlib we can take the following stepsStepsSet the figure size and adjust the padding between and around the subplots.Create a new figure or activate an existing figure.Add an 'ax' to the figure as part of a subplot arrangement.Plot the line with some degree, color='green' and linewidth=2.Create x and y data points, with some curve and plot them using plot() method.To display the figure, use Show() method.Examplefrom matplotlib import pyplot as plt from scipy.interpolate import interp1d import numpy as np plt.rcParams["figure.figsize"] = [7.00, 3.50] plt.rcParams["figure.autolayout"] = True fig = plt.figure() ax ... Read More

To animate with contours in matplotlib, we can take the following stepsStepsSet the figure size and adjust the padding between and around the subplots.Create data for the contour plot.Create a figure and a set of subplots.Generate an animation by repeatedly calling a function *animate* where the animate() method changes the contour data points.To display the figure, use Show() method.Exampleimport numpy as np import matplotlib.pyplot as plt import matplotlib.animation as animation # Set the figure size plt.rcParams["figure.figsize"] = [7.00, 3.50] plt.rcParams["figure.autolayout"] = True # Random data for the contour plot data = np.random.randn(800).reshape(10, 10, 8) # Create a ... Read More

plt.figure() − Creates a new figure or activates an existing figure.plt.subplots() − Creates a figure and a set of subplots.Let's take an example to understand the difference between plt.subplots() and plt.figure().StepsSet the figure size and adjust the padding between and around the subplots.Create a new figure or activate an existing figure. Use plt.figure() method.Create a figure and a set of subplots. Use plt.subplots() method.To display the figure, use Show() method.Examplefrom matplotlib import pyplot as plt # Set the figure size plt.rcParams["figure.figsize"] = [7.00, 3.50] plt.rcParams["figure.autolayout"] = True # Create a new figure using plt.figure fig1 = plt.figure("Figure 1 ... Read More

To get the (x, y) positions pointing with mouse in an interactive plot, we can take the following stepsStepsSet the figure size and adjust the padding between and around the subplots.Create a new figure or activate an existing figure.Bind the function *mouse_event* to the event *button_press_event*.Create x and y data points using numpy.Plot the x and y data points using plot() method.To display the figure, use Show() method.Exampleimport numpy as np from matplotlib import pyplot as plt plt.rcParams["figure.figsize"] = [7.00, 3.50] plt.rcParams["figure.autolayout"] = True def mouse_event(event): print('x: {} and y: {}'.format(event.xdata, event.ydata)) fig = ... Read More

Suppose, we are given a number n and are asked to write all the possible permutations with the positive integers up to n. The permutations are then sorted lexicographically and numbered from 1 to n. Among all the permutations, one permutation is taken and is termed as the special permutation. Now, among the special permutation; the values can be forgotten. The forgotten values are then replaced with 0s. We have to find the permutations that can be equal to the original permutations and then we add their perspective number to obtain a sum. The sum value is returned as the ... Read More

To create a custom mouse cursor in matplotlib, we can take the following stepsStepsSet the figure size and adjust the padding between and around the subplots.Create a new figure or activate an existing figure.Bind the function *mouse_event* to the event *button_press_event*.Create x and y data points using numpy.Plot the x and y data points using plot() method.To display the figure, use Show() method.Exampleimport numpy as np from matplotlib import pyplot as plt plt.rcParams["figure.figsize"] = [7.00, 3.50] plt.rcParams["figure.autolayout"] = True def mouse_event(event):     print('x: {} and y: {}'.format(event.xdata, event.ydata)) fig = plt.figure() cid = fig.canvas.mpl_connect('button_press_event', mouse_event) ... Read More

To read an input image and print it into an array in matplotlib, we can take the following stepsStepsSet the figure size and adjust the padding between and around the subplots.Read an image from a file into an array. Use plt.imread() method.Print the Numpy array of the image.To turn off the axis, use axis('off') method.To display the figure, use Show() method.Examplefrom matplotlib import pyplot as plt plt.rcParams["figure.figsize"] = [7.00, 3.50] plt.rcParams["figure.autolayout"] = True im = plt.imread("forest.jpg") print("Numpy array of the image is: ", im) im = plt.imshow(im) plt.axis('off') plt.show()OutputIt will produce the following output −On the ... Read More

Suppose, we have to build a string 'str' that is of length n. To build the string, we can perform two operations.A character can be added to the end of str for cost a.A substring sub_str can be added to the end of the str for cost r.We have to calculate the minimum cost of building the string str.So, if the input is like a = 5, r = 4, str = 'tpoint', then the output will be 29.To build the string 'tpoint', the cost is described below −str = 't'; a new character added, therefore the cost is 5. ... Read More

To create minor ticks for a polar plot in matplotlib, we can take the following stepsStepsSet the figure size and adjust the padding between and around the subplots.Create r (radius) and theta data points using numpy.Add a subplot to the current figure.Iterate the points between 0 to 360 with step=10 and plot them to get the ticks.To display the figure, use Show() method.Exampleimport numpy as np import matplotlib.pyplot as plt # Set the figure size plt.rcParams["figure.figsize"] = [7.00, 3.50] plt.rcParams["figure.autolayout"] = True # radius and theta for the polar plot r = np.arange(0, 5, 0.1) theta = 2 ... Read More