9 examples of 'drop a column in python' in Python

97
def drop_column(column_name, table, metadata=None):
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    """
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    :param table: Table to drop the column from
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    :type table: :class:`Table` or str
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    :param metadata: Needed only if ``table`` is a table name
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    :type metadata: :class:`Metadata`
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    """
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    try:
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        if not isinstance(table, Table):
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            assert metadata is not None
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            table = Table(table, metadata, autoload=True)
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        column = table.c[column_name]
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        column.drop()
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    except Exception:
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        log.exception("Dropping column '%s' from table '%s' failed.", column_name, table)

47
def drop_not_null(self, col):
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    print('Migrating==> [%s] drop_not_null: %s' % (self._name, col))
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    return self.migrator.drop_not_null(self._name, col)

65
def delete_column(self, table_name, field_name):
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    sql = "ALTER TABLE %s DROP COLUMN %s CASCADE;" % (
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        self.quote_name(table_name),
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        self.quote_name(field_name)
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    )
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    self.execute(sql)

39
def _drop_col(self, df):
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    '''
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    Drops last column, which was added in the parsing procedure due to a
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    trailing white space for each sample in the text file
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    Arguments:
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        df: pandas dataframe
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    Return:
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        df: original df with last column dropped
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    '''
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    return df.drop(df.columns[-1], axis=1)

605
def drop_index(self, name, table):
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    return "DROP INDEX %s;" % self.quote(name)

78
def drop(table_name, cursor):
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    '''
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    |  drop *table_name*
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    '''
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    sql = "DROP TABLE IF EXISTS " + str(table_name)
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    read(sql, cursor)

569
def drop_primary_key(self, table_name):
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    """
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    Drops the old primary key.
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    """
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    qn = connection.ops.quote_name
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    self.execute(self.drop_primary_key_string % {
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        "table": qn(table_name),
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        "constraint": qn(table_name+"_pkey"),

2258
def visit_drop_index(self, drop):
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    index = drop.element
2260
    return "\nDROP INDEX " + self._prepared_index_name(
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        index, include_schema=True)

32
@generic.copy_column_constraints
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@generic.delete_column_constraints
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def rename_column(self, table_name, old, new):
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    if old == new:
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        # Short-circuit out
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        return []
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    self.execute(
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        "ALTER TABLE %s RENAME COLUMN %s TO %s;"
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        % (self.quote_name(table_name), self.quote_name(old), self.quote_name(new))
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    )