Chapter folders renamed

Chapter04/files/1.txt

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+This is a sample file 1
+This is a test data 1

Chapter04/files/2.txt

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+This is a sample file 2
+This is a test data 2

Chapter04/files/contextmgr1.py

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+#contextmgr1.py
+with open("myfile.txt",'w') as f1:
+    f1.write("This is a sample file\n")
+    lines = ["This is a test data\n", "in two lines\n"]
+    f1.writelines(lines)
+
+with open("myfile.txt",'r') as f2:
+    for line in f2.readlines():
+        print(line)

Chapter04/files/multifilesread1.py

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+#multifilesread1.py
+
+with open("1.txt") as file1, open("2.txt") as file2:
+    print(file2.readline())
+    print(file1.readline())

Chapter04/files/multifilesread2.py

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+#multifilesread2.py
+
+with open("1.txt",'r') as file1, open("3.txt",'w') as file2:
+   for line in file1.readlines():
+     file2.write(line)

Chapter04/files/multifilesread3.py

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+#multifilesread2.py
+import fileinput
+with fileinput.input(files = ("1.txt",'2.txt') )as f:
+    for line in f:
+        print(f.filename())
+        print(line)

Chapter04/files/myfile.txt

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+This is a sample file
+This is a test data
+in two lines

Chapter04/files/writereadfile.py

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+#writereadfile.pywrite to a file and then read from it
+f1 = open("myfile.txt",'w')
+f1.write("This is a sample file\n")
+lines =["This is a test data\n", "in two lines\n"]
+f1.writelines(lines)
+f1.close()
+
+f2 = open("myfile.txt",'r')
+print(f2.read(4))
+print(f2.readline())
+print(f2.readline())
+
+f2.seek(0)
+for line in f2.readlines():
+    print(line)
+f2.close()