# Noemi Cabrera # 14 November 2021 # In this lesson, I learned how to identify the platform running a Python script ('Linux', 'win32', 'Darwin') using sys, how to get # the current working directory using os.getcwd(), how to change the current working directory using oschdir(), how to list the content # of the current working directory using os.listdir(), how to create a new directory using os.mkdir(), how to remove a directory using # os.rmdir(), how to rename files and directories using os.rename(). Additionally, I learned to recognize the difference between relative # and absolute paths, as well as how to test whether a path exists using os.path.exists. Lastly, to test whether a specific file or directory # exists, I used os.path.isfile and os.path.isdir. # I had some difficulties trying to figure out why this notebook said some files/directories didn't exist even though the code for the # examples that I have to run were supposed to be correct. Since this was a problem with the code already provided to me, I do not know # how to fix it.

# ************** DO NOT MODIFY OR ADD ANYTHING TO THIS CODE SEGMENT *********** # ************** Click Edit> Clear All Outputs *********** # ************** This code segment must be run before attempting any of the tasks or examples in this lesson ******************** # ************** This cell is a reset cell to remove (if they exist) the parent_dir and any children or leaves # It prepares the directories and files necessary to run the examples and complete the tasks. # This cell can be run first then all others cells in this notebook can be run, then this cell can be rerun # This is the reset. It uses the import shutil (or shell utility) which you will learn later in the course import os, shutil # shutil = shell utility has an important method called rmtree() # linux does not have an equivalent command! # Navigate to `library` directory (if not already in it) current_path = os.getcwd() print(current_path) if ("content" in current_path): #JGif ("library" in current_path): nb_path = current_path.split("content")[0] # nb_path = the 1st item in the split list else: nb_path = current_path print("Changing working dir to directory above parent_dir") os.chdir(os.path.join(nb_path,"content")) current_path = os.getcwd() print("Current working directory:", current_path) if (os.path.exists('parent_dir') == True): shutil.rmtree('parent_dir') os.mkdir('parent_dir') os.chdir('parent_dir') file_path = "./parent_leaf.txt" f = open(file_path, 'w') f.close() file_path = "./text_file.txt" f = open(file_path, 'w') f.close() os.mkdir('child1_dir') os.chdir('child1_dir') file_path = "./leaf1.txt" f = open(file_path, 'w') f.close() os.chdir('../') os.mkdir('child2_dir') os.chdir('child2_dir') file_path = "./leaf2.txt" f = open(file_path, 'w') f.close() os.chdir('../..') current_path = os.getcwd() print("Current working directory:", current_path)

# IN this code, the words 'sys' and 'platform' are used to identify what operating system is # being used. In this case, the operating system is linux.await import sys print(sys.platform)

# In this code, the os module is used. The current working directory is changed to parent_dir, # then to child1_dir, then back to parent_dir by using r using os.chdir(). There is a printout # of the current working directory at every step, which was done by using os.getcwd() in the # print statement. import os # Change the current working directory to parent dir os.chdir('parent_dir') print('Changed working dir to parent: ', os.getcwd()) # Change the current working directory to child1 dir os.chdir('child1_dir') print('Changed working dir to child1: ', os.getcwd()) # Change the current working directory back to the parent dir os.chdir('..') print('Changed working dir back to parent: ', os.getcwd())

# In this code the os module is used. There is a printout of the current working directory, # which was done by using os.getcwd() in the print statement. The contents of the directory # are accessed by using os.listdir(). import os # Print the current working directory (should be "parent_dir") print('The current working directory is:', os.getcwd()) # List the content of the directory (both files and other directories) print('Current directory content: ', os.listdir())

# In this code the os module is used. There is a printout of the current working directory, # which was done by using os.getcwd() in the print statement. Then, a new directory named # "new child" is created by using os.mkdir(). This directory is then removed from the current # directory by using os.rmdir(). import os # Print the current working directory (should be "parent_dir") print('The current working directory is:', os.getcwd()) # Create a new directory os.mkdir('new_child') print('Created new_child dir') # List the content of the directory print('Current directory content: ', os.listdir()) # Remove the new child directory os.rmdir('new_child') print('Removed new_child dir') # List the content of the directory print('Current directory content: ', os.listdir())

# In this code the os module is used. There is a printout of the current working directory, # which was done by using os.getcwd() in the print statement. Then, a new directory named # "new child" is created by using os.mkdir(). This new directory is renamed to "old child" using # os.rename(). This directory is then removed from the current directory by using os.rmdir(). import os # Print the current working directory (should be "parent_dir") print('The current working directory is:', os.getcwd()) # Create a new directory os.mkdir('new_child') print('Created new_child dir') # List the content of the directory print('Current directory content:', os.listdir()) # Rename new_child as old_child os.rename('new_child', 'old_child') print('Renamed new_child as old_child') # List the content of the dir print('Current directory content: ', os.listdir()) # Remove the old_child dir os.rmdir('old_child') print('Removed old_child dir') print('Current directory content: ', os.listdir())

# # In this code the os module is used. The user is asked to enter a file name. Then a # directory is created with the name the user entered. There is a printout displaying the # contents of the current working directory, which was done by using os.listdir() in the # print statement. This directory is then removed from the current directory by using # os.rmdir(). Lastly, there is a printout displaying the contents of the current working directory # [ ] Write a program to: # 1) Prompt the user for a directory name # 2) Create the directory # 3) Verify the directory was created by listing the content of the current working directory # 4) Remove the created directory # 5) Verify the directory was removed by listing the content of the current working directory import os dir_name = input("Enter a directory(file) name:") os.mkdir(dir_name) print('Current directory content: ', os.listdir()) os.rmdir(dir_name) print('Current directory content: ', os.listdir())

# In this code, the os module is used. A directory named "my_dir" is created using os.mkdir() # and then the location is moved to this new file. There is a printout of the current working # directory, which was done by using os.getcwd() in the print statement. Then, the location is # moved to the parent directory using os.chdir(). The "my_dir" directory is renamed to "your_dir" # using os.rename(). This directory is then removed from the current directory by using os.rmdir(). # [ ] Write a program to: # 1) Create a directory called "my_dir" # 2) Change the current working directory to "my_dir" # 3) Verify you are in the correct directory by displaying the current working directory # 4) Change the working directory back to the parent directory # 5) Verify you are in the correct directory by displaying the current working directory # 6) Rename "my_dir" to "your_dir" # 7) Verify the directory was renamed by listing the content of the current working directory # 8) Remove "your_dir" # 9) Verify the directory was removed by listing the content of the current working directory import os os.mkdir("my_dir") os.chdir("my_dir") print('The current working directory is:', os.getcwd()) os.chdir("/work") print('The current working directory is:', os.getcwd()) os.rename("my_dir", "your_dir") print('Current directory content: ', os.listdir()) os.rmdir("your_dir") print('Current directory content: ', os.listdir())

# In this code, the os module is used. There is a printout of the current working # directory, which was done by using os.getcwd() in the print statement, and a printout of # the path to get to the current directory. # Then, using the os.path.abspath() method, the absolute path to child1_dir/leaf1.txt is # stored ito the abs_path variable and displayed. The, the path is tested to see if it exists # using the os.path.exists() method. If it exists, then the type (file directory) of it it's displayed. # If it doesn't exist, then a printout sayig that is displayed. import os, os.path # Print the current working directory (should be "parent_dir") print('The current working directory is:', os.getcwd()) print(os.path) # Find the absolute path to child1_dir/leaf1.txt abs_path = os.path.abspath("child1_dir/leaf1.txt") print("Absolute path to leaf1.txt is: ", abs_path) # Test whether the path exists if(os.path.exists(abs_path)): print("Path exists") # Test to see if it's a file or directory if(os.path.isfile(abs_path)): print("It's a file") elif (os.path.isdir(abs_path)): print("It's a dir") else: print("Path doesn't exist")

# In this code, the os module is used. The user asked to enter a file name, which is stored in # the 'file_name' variable. Then a printout of the current working directory is displayed by using # os.getcwd(). Lastly, if the file name given by the user is found exists in the current working # directory, then a statement saying so will display. If it doesn't exist in the current working # directory, then a statement saying so will display. # [ ] Write a program that prompts the user for a file or directory name # then prints a message verifying if it exists in the current working directory import os file_name = input("Enter a file name: ") print('The current working directory is:', os.getcwd()) print(os.path) print() if(os.path.exists(file_name)): print(file_name, "exists in the current working directory") else: print(file_name, "- doesn't exist in the current working directory")

# In this code, the os module is used. A printout of the current working directory is displayed # by using os.getcwd(). Then, the contents of the this directory is dislpayed by using o.listdir(). # Lastly, a for..in loop interates through each item in the contents and displays the absolute path # for each item. # [ ] Write a program to print the absolute path of all directories in "parent_dir" # HINTS: # 1) Verify you are inside "parent_dir" using os.getcwd() # 2) Use os.listdir() to get a list of files and directories in "parent_dir" # 3) Iterate over the elements of the list and print the absolute paths of all the directories import os print('The current working directory is:', os.getcwd()) print(os.listdir("parent_dir")) for element in parent_dir: if(os.path.exists(item)): print(os.path.abspath(item))