Create project 1.py

Author: AsmaaEssamSultan

Diff for: Course 2/project 1.py

@@ -0,0 +1,181 @@
+"""
+Project for Week 4 of "Python Data Representations".
+Find differences in file contents.
+
+Be sure to read the project description page for further information
+about the expected behavior of the program.
+"""
+
+IDENTICAL = -1
+
+def singleline_diff(line1, line2):
+    """
+    Inputs:
+      line1 - first single line string
+      line2 - second single line string
+    Output:
+      Returns the index where the first difference between
+      line1 and line2 occurs.
+
+      Returns IDENTICAL if the two lines are the same.
+    """
+    length1 = len(line1)
+    length2 = len(line2)
+
+    if length1 <= length2:
+        min_length = length1
+    else:
+        min_length = length2
+
+    if line1 == line2 :
+        return IDENTICAL
+    else:
+        for index in range(min_length):
+            if line1[index] != line2[index]:
+                return index
+        return min_length
+
+
+def singleline_diff_format(line1, line2, idx):
+    """
+    Inputs:
+      line1 - first single line string
+      line2 - second single line string
+      idx   - index at which to indicate difference
+    Output:
+      Returns a three line formatted string showing the location
+      of the first difference between line1 and line2.
+
+      If either input line contains a newline or carriage return,
+      then returns an empty string.
+
+      If idx is not a valid index, then returns an empty string.
+    """
+    length1 = len(line1)
+    length2 = len(line2)
+    word = ""
+    index = 0
+
+    if line1.find("\n") >= 0 or line2.find("\n") >= 0:
+        word += ""
+    elif line1.find("\t") >= 0 or line2.find("\t") >= 0:
+        word += ""
+
+    if idx > length1 or idx > length2 or idx < 0:
+        return ""
+
+    if length1 == length2:
+        if idx == -1:
+            return ""
+        else:
+            while index < idx:
+                word += "="
+                index += 1
+            word += "^"
+    elif length1 < length2:
+        while index < idx:
+            word += "="
+            index += 1
+        word += "^"
+    elif length1 > length2:
+        while index < idx:
+            word += "="
+            index += 1
+        word += "^"
+
+    new_word = line1 + "\n" + word + "\n" + line2 + "\n"
+
+    return new_word
+
+def multiline_diff(lines1, lines2):
+    """
+    Inputs:
+      lines1 - list of single line strings
+      lines2 - list of single line strings
+    Output:
+      Returns a tuple containing the line number (starting from 0) and
+      the index in that line where the first difference between lines1
+      and lines2 occurs.
+
+      Returns (IDENTICAL, IDENTICAL) if the two lists are the same.
+    """
+    length1 = len(lines1)
+    length2 = len(lines2)
+
+    if length1 < length2 :
+        min_length = length1
+    else:
+        min_length = length2
+    if length1 == length2 and lines1 != lines2 :
+        for index in range(length1):
+            line1 = lines1[index]
+            line2 = lines2[index]
+            diff_index = singleline_diff(line1,line2)
+            if diff_index >= 0:
+                return (index , diff_index)
+
+
+    elif length1 < length2 or length2 < length1 :
+        if min_length == 0:
+            return ( min_length , 0)
+        elif lines1[min_length-1] == lines2[min_length-1] :
+            return (min_length , 0)
+        else:
+            for index in range(min_length):
+                line1 = lines1[index]
+                line2 = lines2[index]
+                diff_index = singleline_diff(line1,line2)
+            return (index , diff_index)
+    return  (IDENTICAL, IDENTICAL)
+
+
+def get_file_lines(filename):
+    """
+    Inputs:
+      filename - name of file to read
+    Output:
+      Returns a list of lines from the file named filename.  Each
+      line will be a single line string with no newline ('\n') or
+      return ('\r') characters.
+
+      If the file does not exist or is not readable, then the
+      behavior of this function is undefined.
+    """
+
+    file = open(filename , "rt")
+
+    the_list = []
+    for line in file :
+        new_line = line.rstrip()
+        the_list.append(new_line)
+
+    file.close()
+    return the_list
+
+def file_diff_format(filename1, filename2):
+    """
+    Inputs:
+      filename1 - name of first file
+      filename2 - name of second file
+    Output:
+      Returns a four line string showing the location of the first
+      difference between the two files named by the inputs.
+
+      If the files are identical, the function instead returns the
+      string "No differences\n".
+
+      If either file does not exist or is not readable, then the
+      behavior of this function is undefined.
+    """
+    file1 = get_file_lines(filename1)
+    file2 = get_file_lines(filename2)
+    line_index = multiline_diff(file1 , file2)
+
+    if line_index == (-1, -1):
+        return "No differences\n"
+    else:
+        num_of_line = line_index[0]
+        num_of_index = line_index[1]
+        output = "Line " + str(num_of_line) +":\n" + \
+        singleline_diff_format(file1[num_of_line],file2[num_of_line],num_of_index)
+        return output