Create mysqldump_to_csv_and_txt.py

mysqldump_to_csv_and_txt.py

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+import fileinput
+import csv
+import sys
+
+# This prevents prematurely closed pipes from raising
+# an exception in Python
+from signal import signal, SIGPIPE, SIG_DFL
+signal(SIGPIPE, SIG_DFL)
+
+# allow large content in the dump
+csv.field_size_limit(sys.maxsize)
+
+def is_create(line):
+    """
+    Returns true if the line begins with a SQL create statement.
+    """
+    return line.startswith('CREATE TABLE') or False
+
+def is_insert(line):
+    """
+    Returns true if the line begins a SQL insert statement.
+    """
+    return line.startswith('INSERT INTO') or False
+
+def get_tablename(line):
+    """
+    Returns the name of the table working with
+    """
+    from re import search
+    pattern=search(r"`.*`",line)
+    return pattern.group(0).replace(r"`","")
+
+def get_values(line):
+    """
+    Returns the portion of an INSERT statement containing values
+    """
+    return line.partition('` VALUES ')[2]
+
+
+def values_sanity_check(values):
+    """
+    Ensures that values from the INSERT statement meet basic checks.
+    """
+    assert values
+    assert values[0] == '('
+    # Assertions have not been raised
+    return True
+
+
+def parse_values(table_name,values, outfile):
+    """
+    Given a file handle and the raw values from a MySQL INSERT
+    statement, write the equivalent CSV to the file
+    """
+    latest_row = []
+    reader = csv.reader([values], delimiter=',',
+                        doublequote=False,
+                        escapechar='\\',
+                        quotechar="'",
+                        strict=True
+    )
+    outfile=open(outfile,"a")
+    writer = csv.writer(outfile, quoting=csv.QUOTE_MINIMAL)
+    for reader_row in reader:
+        for column in reader_row:
+            # If our current string is empty...
+            if len(column) == 0 or column == 'NULL':
+                latest_row.append(chr(0))
+                continue
+            # If our string starts with an open paren
+            if column[0] == "(":
+                # Assume that this column does not begin
+                # a new row.
+                new_row = False
+                # If we've been filling out a row
+                if len(latest_row) > 0:
+                    # Check if the previous entry ended in
+                    # a close paren. If so, the row we've
+                    # been filling out has been COMPLETED
+                    # as:
+                    #    1) the previous entry ended in a )
+                    #    2) the current entry starts with a (
+                    if latest_row[-1][-1] == ")":
+                        # Remove the close paren.
+                        latest_row[-1] = latest_row[-1][:-1]
+                        new_row = True
+                # If we've found a new row, write it out
+                # and begin our new one
+                if new_row:
+                    writer.writerow(latest_row)
+                    latest_row = []
+                # If we're beginning a new row, eliminate the
+                # opening parentheses.
+                if len(latest_row) == 0:
+                    column = column[1:]
+            # Add our column to the row we're working on.
+            latest_row.append(column)
+        # At the end of an INSERT statement, we'll
+        # have the semicolon.
+        # Make sure to remove the semicolon and
+        # the close paren.
+        if latest_row[-1][-2:] == ");":
+            latest_row[-1] = latest_row[-1][:-2]
+            writer.writerow(latest_row)
+
+
+def main():
+    """
+    Parse arguments and start the program
+    """
+    # Iterate over all lines in all files
+    # listed in sys.argv[1:]
+    # or stdin if no args given.
+    create_table=False #Flag indicates wheather processing create table command or not
+    tn=""#stores last table name
+    try:
+        for line in fileinput.input():
+            #Look for a create statement and parse it
+            if is_create(line) or create_table:
+                if not create_table:
+                    #Getting table name
+                    tn=get_tablename(line)
+                    create_table=True
+                with open(tn+".txt",'a') as outFile:
+                    outFile.write(line)
+                if ";" in line:
+                    create_table=False
+            # Look for an INSERT statement and parse it.
+            if is_insert(line):
+                #Getting table name
+                tn=get_tablename(line)
+                values = get_values(line)
+                if values_sanity_check(values):
+                    #Each new table name will result in a new file
+                    parse_values(tn,values, tn+".csv")
+    except KeyboardInterrupt:
+        sys.exit(0)
+
+if __name__ == "__main__":
+    main()