replace print statements with clibella functions

udib/clibella.py

@@ -0,0 +1,333 @@
+"""This module provides classes and methods for pretty console output."""
+
+import sys
+
+import colorama
+from colorama import Fore, Style
+
+class _Prefix:
+    """The Prefix class represents text which is prepended to text output.
+
+    Prefixes have an associated colorama color which the prefix text will have.
+
+    Attributes
+    ----------
+    text : str
+        Text displayed as a prefix for a message.
+    color : colorama color constant
+        Color in which the prefix text will be highlighted.
+    """
+
+    # This class variable holds all created Prefix objects.
+    _all_prefixes = []
+
+    def __init__(self, prefix_text, colorama_color):
+        self.text = prefix_text
+        self.color = colorama_color
+        _Prefix._all_prefixes.append(self)
+
+    def get_max_length():
+        """Returns the number of characters of the longest existing prefix.
+
+        If no prefixes exist, returns 0.
+        """
+
+        longest_prefix_length = 0
+        for prefix in _Prefix._all_prefixes:
+            if len(prefix.text) > longest_prefix_length:
+                longest_prefix_length = len(prefix.text)
+
+        return longest_prefix_length
+
+_prefix_info    = _Prefix("INFO", Fore.WHITE)
+_prefix_ok      = _Prefix("OK", Fore.GREEN)
+_prefix_success = _Prefix("SUCCESS", Fore.GREEN)
+_prefix_debug   = _Prefix("DEBUG", Fore.BLUE)
+_prefix_input  = _Prefix("PROMPT", Fore.CYAN)
+_prefix_warning = _Prefix("WARNING", Fore.YELLOW)
+_prefix_error   = _Prefix("ERROR", Fore.RED)
+_prefix_failure = _Prefix("FAILURE", Fore.RED)
+
+class Printer:
+    """Printer objects print prefixed output to the specified output stream."""
+
+    # These class variables are needed to keep track of whether colorama has
+    # been initialized.
+    _num_of_active_printers = 0
+    _colorama_previously_initialized = False
+
+    def __init__(self, file=sys.stdout):
+        """Constructs a Printer object and sets its default behaviour.
+
+        If the created Printer is the first printer that has been created,
+        colorama is initialized.
+        If the newly created Printer is the only printer in existence, but
+        other Printers have existed previously (as indicated by the
+        '_colorama_previously_initialized' class variable), colorama is
+        re-initialized.
+
+        Parameters
+        ----------
+        file : File object
+            The file to which the Printer prints text by default (defaults to
+            stdout).
+        """
+
+        # check if colorama needs to be initialized
+        if not Printer._colorama_previously_initialized:
+            colorama.init()
+            Printer._colorama_previously_initialized = True
+        else:
+            if Printer._num_of_active_printers == 0:
+                colorama.reinit()
+
+        Printer._num_of_active_printers += 1
+
+        self.file = file
+
+    def __del__(self):
+        """Deconstructs a Printer object.
+
+        If the deleted Printer is the last one in existence, colorama is
+        de-initialized.
+        """
+
+        # check if colorama should be de-initialized
+        if Printer._num_of_active_printers == 1:
+            colorama.deinit()
+
+        Printer._num_of_active_printers -= 1
+
+    def _print_prefixed_output(self, prefix, *args, color_enabled=True, **kwargs):
+        """Prints the output with the specified prefix prepended.
+
+        This method works the same as the standard library print() function,
+        but with the colored text specified by the input prefix object
+        prepended to the printed output.
+        The output stream to which the output is printed is the one specified
+        in this Printer object's file attribute.
+
+        Parameters
+        ----------
+        prefix : Prefix object
+            The prefix prepended to the output.
+        *args : various
+            The printable object(s) to be printed.
+        color_enabled : bool
+            If True, the printed output prefix is colored.
+            If False, the printed output prefix is not colored.
+        **kwargs : various
+            The same keywords which the builtin print() function accepts, with
+            the exception of the "file" argument.
+        """
+
+        prefix_str = ""
+        prefix_text = prefix.text.center(_Prefix.get_max_length())
+
+        if color_enabled:
+            prefix_str = f"[{prefix.color}{prefix_text}{Style.RESET_ALL}] "
+        else:
+            prefix_str = f"[{prefix_text}] "
+
+        print(prefix_str, end='', sep='', file=self.file)
+        print(*args, **kwargs, file=self.file)
+
+    def _get_prefixed_input(self, prefix, *args, color_enabled=True, **kwargs):
+        """Prints the input prompt with the specified prefix prepended.
+
+        This method works the same as the standard library input() function,
+        but with the colored text specified by the input prefix object
+        prepended to the printed output.
+        The output stream to which the output is printed is always stdout.
+
+        Parameters
+        ----------
+        prefix : Prefix object
+            The prefix prepended to the output.
+        *args : various
+            The printable object(s) to be printed.
+        color_enabled : bool
+            If True, the printed output prefix is colored.
+            If False, the printed output prefix is not colored.
+        **kwargs : various
+            The same keywords which the builtin print() function accepts, with
+            the exception of the "file" argument.
+        """
+
+        prefix_str = ""
+        prefix_text = prefix.text.center(_Prefix.get_max_length())
+
+        if color_enabled:
+            prefix_str = f"[{prefix.color}{prefix_text}{Style.RESET_ALL}] "
+        else:
+            prefix_str = f"[{prefix_text}] "
+
+        print(prefix_str, end='', sep='', file=sys.stdout)
+        return input(*args, **kwargs)
+
+    def info(self, *args, color_enabled=True, **kwargs):
+        """Prints the specified input with an "[INFO] " prefix prepended.
+
+        Parameters
+        ----------
+        *args : various
+            The printable object(s) to be printed.
+        color_enabled : Bool
+            Whether or not the prefix text is colored.
+        **kwargs : various
+            The same keywords which the builtin print() function accepts, with
+            the exception of the "file" argument.
+        """
+
+        self._print_prefixed_output(
+            _prefix_info,
+            *args,
+            color_enabled=color_enabled,
+            **kwargs
+        )
+
+    def ok(self, *args, color_enabled=True, **kwargs):
+        """Prints the specified input with an "[OK] " prefix prepended.
+
+        Parameters
+        ----------
+        *args : various
+            The printable object(s) to be printed.
+        color_enabled : Bool
+            Whether or not the prefix text is colored.
+        **kwargs : various
+            The same keywords which the builtin print() function accepts, with
+            the exception of the "file" argument.
+        """
+
+        self._print_prefixed_output(
+            _prefix_ok,
+            *args,
+            color_enabled=color_enabled,
+            **kwargs
+        )
+
+    def success(self, *args, color_enabled=True, **kwargs):
+        """Prints the specified input with a "[SUCCESS] " prefix prepended.
+
+        Parameters
+        ----------
+        *args : various
+            The printable object(s) to be printed.
+        color_enabled : Bool
+            Whether or not the prefix text is colored.
+        **kwargs : various
+            The same keywords which the builtin print() function accepts, with
+            the exception of the "file" argument.
+        """
+
+        self._print_prefixed_output(
+            _prefix_success,
+            *args,
+            color_enabled=color_enabled,
+            **kwargs
+        )
+
+    def debug(self, *args, color_enabled=True, **kwargs):
+        """Prints the specified input with a "[DEBUG] " prefix prepended.
+
+        Parameters
+        ----------
+        *args : various
+            The printable object(s) to be printed.
+        color_enabled : Bool
+            Whether or not the prefix text is colored.
+        **kwargs : various
+            The same keywords which the builtin print() function accepts, with
+            the exception of the "file" argument.
+        """
+
+        self._print_prefixed_output(
+            _prefix_debug,
+            *args,
+            color_enabled=color_enabled,
+            **kwargs
+        )
+
+    def warning(self, *args, color_enabled=True, **kwargs):
+        """Prints the specified output with a "[WARNING] " prefix prepended.
+
+        Parameters
+        ----------
+        *args : various
+            The printable object(s) to be printed.
+        color_enabled : Bool
+            Whether or not the prefix text is colored.
+        **kwargs : various
+            The same keywords which the builtin print() function accepts, with
+            the exception of the "file" argument.
+        """
+
+        self._print_prefixed_output(
+            _prefix_warning,
+            *args,
+            color_enabled=color_enabled,
+            **kwargs
+        )
+
+    def error(self, *args, color_enabled=True, **kwargs):
+        """Prints the specified output with an "[ERROR] " prefix prepended.
+
+        Parameters
+        ----------
+        *args : various
+            The printable object(s) to be printed.
+        color_enabled : Bool
+            Whether or not the prefix text is colored.
+        **kwargs : various
+            The same keywords which the builtin print() function accepts, with
+            the exception of the "file" argument.
+        """
+
+        self._print_prefixed_output(
+            _prefix_error,
+            *args,
+            color_enabled=color_enabled,
+            **kwargs
+        )
+
+    def failure(self, *args, color_enabled=True, **kwargs):
+        """Prints the specified output with a "[FAILURE] " prefix prepended.
+
+        Parameters
+        ----------
+        *args : various
+            The printable object(s) to be printed.
+        color_enabled : Bool
+            Whether or not the prefix text is colored.
+        **kwargs : various
+            The same keywords which the builtin print() function accepts, with
+            the exception of the "file" argument.
+        """
+
+        self._print_prefixed_output(
+            _prefix_failure,
+            *args,
+            color_enabled=color_enabled,
+            **kwargs
+        )
+
+    def input(self, *args, color_enabled=True, **kwargs):
+        """Prompts the user for input with the "[PROMPT] " prefix prepended.
+
+        Parameters
+        ----------
+        *args : various
+            The printable object(s) to be printed.
+        color_enabled : Bool
+            Whether or not the prefix text is colored.
+        **kwargs : various
+            The same keywords which the builtin input() function accepts.
+        """
+
+        return self._get_prefixed_input(
+            _prefix_input,
+            *args,
+            color_enabled=color_enabled,
+            **kwargs
+        )

udib/gpgverify.py

@@ -7,7 +7,11 @@ from pathlib import Path
 import gnupg
 
 import userinput
-from printmsg import perror, pfailure, pinfo, pok, psuccess, pwarning
+import clibella
+
+
+p = clibella.Printer()
+
 
 def gpg_signature_is_valid(
         path_to_signature_file,
@@ -47,7 +51,7 @@ def gpg_signature_is_valid(
     gpg = gnupg.GPG()
     gpg.encoding = "utf-8"
 
-    pinfo("Validating signature...")
+    p.info("Validating signature...")
     with open(path_to_signature_file, "rb") as signature_file:
         verification = gpg.verify_file(
             signature_file,
@@ -61,20 +65,20 @@ def gpg_signature_is_valid(
             f"Not a valid PGP signature file: '{path_to_signature_file}'."
         )
     else:
-        pinfo(f"Signature mentions a key with ID "\
+        p.info(f"Signature mentions a key with ID "\
               f"{verification.key_id} and fingerprint "\
               f"{verification.fingerprint}."
         )
 
     if verification.valid:
-        pok(f"GPG signature is valid with trustlevel "\
+        p.ok(f"GPG signature is valid with trustlevel "\
               f"'{verification.trust_level}'."
         )
         return True
 
     # this case commonly occurrs when the GPG key has not been imported
     if verification.status == "no public key":
-        pwarning("Could not find the public GPG key locally!")
+        p.warning("Could not find the public GPG key locally!")
 
         # prompt user until answer is unambiguous
         key_will_be_imported = None
@@ -85,30 +89,30 @@ def gpg_signature_is_valid(
             )
 
             if key_will_be_imported is None:
-                perror("Unrecognized input. Please try again.")
+                p.error("Unrecognized input. Please try again.")
 
         if not key_will_be_imported:
-            pwarning("Aborting without importing key.")
+            p.warning("Aborting without importing key.")
             return False
 
         # import missing key
-        pinfo("Importing key...")
+        p.info("Importing key...")
         import_result = gpg.recv_keys(
             fallback_keyserver_name, verification.key_id
         )
 
         if import_result.count < 1:
-            perror("Failed to import key.")
+            p.error("Failed to import key.")
             return False
 
         # display some of gpg's output
         gpg_output = import_result.stderr.split('\n')
         for line in gpg_output:
             if line.startswith("gpg: "):
-                pinfo(f"{line}")
+                p.info(f"{line}")
 
     # validate signature again
-    pinfo("Validating signature...")
+    p.info("Validating signature...")
     with open(path_to_signature_file, "rb") as signature_file:
         verification = gpg.verify_file(
             signature_file,
@@ -117,10 +121,10 @@ def gpg_signature_is_valid(
         )
 
     if verification.valid:
-        pok(f"GPG signature is valid with trustlevel "\
+        p.ok(f"GPG signature is valid with trustlevel "\
               f"'{verification.trust_level}'."
         )
         return True
     else:
-        perror("GPG signature is not valid!!!")
+        p.error("GPG signature is not valid!!!")
         return False

udib/userinput.py

@@ -4,7 +4,11 @@
 
 import re
 
-from printmsg import pinput
+import clibella
+
+
+p = clibella.Printer()
+
 
 def prompt_yes_or_no(question, ask_until_valid = False):
     """ Prompts the user with the specified yes/no question.
@@ -37,7 +41,7 @@ def prompt_yes_or_no(question, ask_until_valid = False):
     regex_no  = re.compile(r"^(n)$|^(N)$|^(NO)$|^(No)$|^(no)$")
 
     while(not user_input_is_valid):
-        user_input = pinput(f"{question} (Yes/No): ")
+        user_input = p.input(f"{question} (Yes/No): ")
 
         if (regex_yes.match(user_input)):
             return True
@@ -45,4 +49,3 @@ def prompt_yes_or_no(question, ask_until_valid = False):
             return False
         elif (not ask_until_valid):
             return None
-

udib/webdownload.py

@@ -10,9 +10,13 @@ import requests
 from bs4 import BeautifulSoup
 from tqdm import tqdm
 
-from printmsg import perror, pfailure, pinfo, pok, psuccess, pwarning
+import clibella
 import gpgverify
 
+
+p = clibella.Printer()
+
+
 def download_file(path_to_output_file, url_to_file, show_progress = False):
     """ Downloads the file at the specified URL via HTTP and saves it as the
         specified output file. Optionally, displays a nice status bar.
@@ -40,7 +44,7 @@ def download_file(path_to_output_file, url_to_file, show_progress = False):
 
     output_file_name = path_to_output_file.name
     with open(path_to_output_file, "wb") as output_file:
-        pinfo(f"Downloading '{output_file_name}'...")
+        p.info(f"Downloading '{output_file_name}'...")
         file_response = requests.get(url_to_file, stream=True)
         total_length = file_response.headers.get('content-length')
 
@@ -64,7 +68,7 @@ def download_file(path_to_output_file, url_to_file, show_progress = False):
             if (show_progress):
                 progress_bar.close()
 
-        pok(f"Received '{output_file_name}'.")
+        p.ok(f"Received '{output_file_name}'.")
 
 def debian_obtain_image(path_to_output_dir):
     """ Obtains the latest official debian installation image, the SHA512SUMS
@@ -90,7 +94,7 @@ def debian_obtain_image(path_to_output_dir):
         Full path to the obtained and validated image file.
     """
 
-    pinfo("Obtaining and verifying the latest Debian stable image...")
+    p.info("Obtaining and verifying the latest Debian stable image...")
 
     path_to_output_dir = Path(path_to_output_dir)
 
@@ -147,7 +151,7 @@ def debian_obtain_image(path_to_output_dir):
         hash_file.writelines(hash_file_lines_to_keep)
 
     # validate SHA512 checksum
-    pinfo("Validating file integrity...")
+    p.info("Validating file integrity...")
     hash_check_result = subprocess.run(
         ["sha512sum", "--check", path_to_output_dir / hash_file_name],
         capture_output = True,
@@ -160,22 +164,22 @@ def debian_obtain_image(path_to_output_dir):
     if len(stdout_lines) > 0:
         for line in stdout_lines:
             if len(line) > 0:
-                pinfo(f"{line}")
+                p.info(f"{line}")
 
     if hash_check_result.returncode != 0:
         if len(stderr_lines) > 0:
             for line in stderr_lines:
                 if len(line) > 0:
-                    perror(f"{line}")
+                    p.error(f"{line}")
         raise RuntimeError("SHA512 validation failed.")
 
-    pok("File integrity checks passed.")
+    p.ok("File integrity checks passed.")
 
     # clean up obsolete files
-    pinfo("Cleaning up files...")
+    p.info("Cleaning up files...")
     os.remove(path_to_output_dir / hash_file_name)
     os.remove(path_to_output_dir / signature_file_name)
 
-    psuccess("Debian image obtained.")
+    p.success("Debian image obtained.")
 
     return str(path_to_output_dir / image_file_name)