Please explain well in python Hints:You only need to alter the vertex lines (the onesstarting with 'v'); the lines starting with 'f' canjust be copied directly from the input file into theoutput file.• If you want to see text contents of an OBJ filerather than the 3D model, be sure to open the filewith a text editor (like Atom) and not somethinglike 3D Model Viewer.• You can convert a line from the OBJ file into a listwith the statement●Constraints:-1listName =stringName.split(' ').You can convert this list back into a string withthe statementstringName9Examples (assumes that missing.obj does not exist withinyour current directory): stretch_model('missing.obj','doesntmatter.obj')=You may use any string or list method that isappropriate to solving this problem.All files must be properly opened and closed. stretch_model('triforce.obj','.join(listName).'triforce_stretched.obj')3644 stretch_model('teapot.obj','tall_teapot.obj')triforce.objExample Screenshots: (usinghttp://masc.cs.gmu.edu/wiki/ObjViewer)triforce_stretched.objteapot In computer graphics, 3D objects are stored in files thatare meant to be loaded and displayed on the screen.Although multiple file formats exist for 3D models, OBJis one of the most commonly used. These files are plaintext ending in .obj that contain the following:1) A list of vertices that specifies the x,y,zcoordinates of each point in 3D space2) A list of faces, each of which specifies the indexnumber of three points that form a triangleEach vertex is listed on one line, and begins with theletter v. The x, y, and z coordinates are included next,separated by spaces. After all the vertices are done, eachface is then listed on one line beginning with the letter f.The three index numbers are included next, starting with1, also separated by spaces. For example, this OBJ filecontains a single triangle and would be displayed asfollows:v -1.5 0.0 0.0v 1.0 -2.0 0.0v 0.0 1.5 0.0f 1 2 3Write a function stretch_model(fname_in,fname_out) that reads all the vertices and faces in theOBJ file specified by the string fname_in. The functionshould then transform the vertices to stretch the model bya factor of 2 along the y-axis, and then save thetransformed vertices and faces to a file specified by thestring fname_out. This function should return the totalnumber of vertices that were stretched.If the specified file fname_in does not exist,stretch_model should instead return -1.To stretch the model along the y-axis, the y-coordinate foreach vertex should be multiplied by 2. The x and zcoordinates should not be affected.So, for the example given above, the output file wouldlook like this (note that due to the OBJ model viewerautomatically adjusting the boundaries, the image looksshortened rather than stretched):v -1.5 0.0 0.0v 1.0 -4.0 0.0v 0.0 3.0 0.0f 1 2 3

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Please explain well in python Hints:You only need to alter the vertex lines (the onesstarting with 'v'); the lines starting with 'f' canjust be copied directly from the input file into theoutput file.• If you want to see text contents of an OBJ filerather than the 3D model, be sure to open the filewith a text editor (like Atom) and not somethinglike 3D Model Viewer.• You can convert a line from the OBJ file into a listwith the statement●Constraints:-1listName =stringName.split(' ').You can convert this list back into a string withthe statementstringName9Examples (assumes that missing.obj does not exist withinyour current directory):>>> stretch_model('missing.obj','doesntmatter.obj')=You may use any string or list method that isappropriate to solving this problem.All files must be properly opened and closed.>>> stretch_model('triforce.obj','.join(listName).'triforce_stretched.obj')3644>>> stretch_model('teapot.obj','tall_teapot.obj')triforce.objExample Screenshots: (usinghttp://masc.cs.gmu.edu/wiki/ObjViewer)triforce_stretched.objteapot In computer graphics, 3D objects are stored in files thatare meant to be loaded and displayed on the screen.Although multiple file formats exist for 3D models, OBJis one of the most commonly used. These files are plaintext ending in .obj that contain the following:1) A list of vertices that specifies the x,y,zcoordinates of each point in 3D space2) A list of faces, each of which specifies the indexnumber of three points that form a triangleEach vertex is listed on one line, and begins with theletter v. The x, y, and z coordinates are included next,separated by spaces. After all the vertices are done, eachface is then listed on one line beginning with the letter f.The three index numbers are included next, starting with1, also separated by spaces. For example, this OBJ filecontains a single triangle and would be displayed asfollows:v -1.5 0.0 0.0v 1.0 -2.0 0.0v 0.0 1.5 0.0f 1 2 3Write a function stretch_model(fname_in,fname_out) that reads all the vertices and faces in theOBJ file specified by the string fname_in. The functionshould then transform the vertices to stretch the model bya factor of 2 along the y-axis, and then save thetransformed vertices and faces to a file specified by thestring fname_out. This function should return the totalnumber of vertices that were stretched.If the specified file fname_in does not exist,stretch_model should instead return -1.To stretch the model along the y-axis, the y-coordinate foreach vertex should be multiplied by 2. The x and zcoordinates should not be affected.So, for the example given above, the output file wouldlook like this (note that due to the OBJ model viewerautomatically adjusting the boundaries, the image looksshortened rather than stretched):v -1.5 0.0 0.0v 1.0 -4.0 0.0v 0.0 3.0 0.0f 1 2 3

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Define a function stretch_model that takes two file names, fname_in and fname_out as…