Initial commit

source/08-text-files/fileuse/binaryfile.py

@@ -0,0 +1,42 @@
+
+def write_file():
+    """
+    Écrire un fichier binaire très simple.
+
+    En Python, on ne peut pas tout simplement écrire des chaînes dans un
+    fichier dit binaire. Dans Python 3, on fait la différence entre binaire et texte.
+    Quand on manipule des fichiers texte, on peut y écrire des données `str`.
+    Par contre, quand on manipule des fichiers binaires, on manipule des données plus
+    brutes, de type `bytes` (ou `bytearray`)
+
+    """
+    f = open("demo.bin", "wb")
+    f.write(bytearray([32, 33, 34, 35, 36, 37, 38, 39, 40]))  # (9)
+    f.write(b"Bonjour les amis")  # (16) ça passe car les caractères sont ASCII et leur code tient dans un byte
+    f.write("Bonjour les héros, ça va bien ?".encode("utf-8"))  # (33)
+    f.close()
+
+
+def read_file():
+    """
+    Lire dans un fichier binaire très simple.
+
+    """
+    f = open("demo.bin", "rb")
+    tableau = f.read(9)
+    chaine1 = f.read(16)
+    chaine2 = f.read(33).decode("utf-8")
+    f.seek(0)
+    data = f.read()
+    f.close()
+    # Afficher les données lues dans le fichier
+    print(tableau)
+    print(chaine1)
+    print(chaine2)
+    # Pour tester, revenir au début du fichier et tout lire d'une traite
+    print(data)
+
+
+if __name__ == "__main__":
+    write_file()
+    read_file()

source/08-text-files/fileuse/demo.bin

@@ -0,0 +1 @@
+ !"#$%&'(Bonjour les amisBonjour les héros, ça va bien ?

source/08-text-files/fileuse/demo.txt

@@ -0,0 +1 @@
+Contenu de notre fichier texte de démo !

source/08-text-files/fileuse/filemanager.py

@@ -0,0 +1,43 @@
+
+with open("demo.txt", "r", encoding="utf-8") as f:
+    pass
+
+# écrire un manager
+class File(object):
+    def __init__(self, file_name, method):
+        self.file_obj = open(file_name, method)
+    def __enter__(self):
+        return self.file_obj
+    def __exit__(self, type, value, traceback):
+        self.file_obj.close()
+
+# Just by defining __enter__ and __exit__ methods we can use our new class in a with statement. Let’s try:
+#
+# with File('demo.txt', 'w') as opened_file:
+#     opened_file.write('Hola!')
+#
+# Our __exit__ method accepts three arguments. They are required by every __exit__ method which is a part of a Context Manager class. Let’s talk about what happens under-the-hood.
+#
+#     The with statement stores the __exit__ method of the File class.
+#     It calls the __enter__ method of the File class.
+#     The __enter__ method opens the file and returns it.
+#     The opened file handle is passed to opened_file.
+#     We write to the file using .write().
+#     The with statement calls the stored __exit__ method.
+#     The __exit__ method closes the file.
+
+
+# We did not talk about the type, value and traceback arguments of the __exit__ method. Between the 4th and 6th step, if an exception occurs, Python passes the type, value and traceback of the exception to the __exit__ method. It allows the __exit__ method to decide how to close the file and if any further steps are required. In our case we are not paying any attention to them.
+#
+# What if our file object raises an exception? We might be trying to access a method on the file object which it does not supports. For instance:
+#
+# with File('demo.txt', 'w') as opened_file:
+#     opened_file.undefined_function('Hola!')
+#
+# Let’s list the steps which are taken by the with statement when an error is encountered:
+#
+#     It passes the type, value and traceback of the error to the __exit__ method.
+#     It allows the __exit__ method to handle the exception.
+#     If __exit__ returns True then the exception was gracefully handled.
+#     If anything other than True is returned by the __exit__ method then the exception is raised by the with statement.
+

source/08-text-files/fileuse/filesearch.py

@@ -0,0 +1,12 @@
+import os, glob
+
+# traverse root directory, and list directories as dirs and files as files
+for root, dirs, files in os.walk("/home/steve/Code/python/initiation"):
+    for filename in files:
+        path = os.path.join(root, filename)
+        print(path)
+
+
+# https://docs.python.org/fr/3/library/glob.html
+files = glob.glob("/home/steve/Code/python/initiation/**/*.py", recursive=True)
+print(files)

source/08-text-files/fileuse/textfile.py

@@ -0,0 +1,25 @@
+
+def write_file():
+    """
+    Écrire un fichier texte très simple.
+
+    """
+    f = open("demo.txt", "w")
+    f.write("Contenu de notre fichier texte de démo e!")
+    f.close()
+
+
+def read_file():
+    """
+    Lire dans un fichier texte très simple.
+
+    """
+    f = open("demo.txt", "r")
+    data = f.read()
+    f.close()
+    print(data)
+
+
+if __name__ == "__main__":
+    write_file()
+    read_file()