ast.fix_missing_locations(node) When you compile a node tree with compile(), the compiler expects lineno and col_offset attributes for every node that supports them. This is rather tedious to fill in for generated nodes, so this helper adds these attributes recursively where not already set, by setting them to the values of the parent node. It works recursively starting at node.

ast.dump(node, annotate_fields=True, include_attributes=False) Return a formatted dump of the tree in node. This is mainly useful for debugging purposes. The returned string will show the names and the values for fields. This makes the code impossible to evaluate, so if evaluation is wanted annotate_fields must be set to False. Attributes such as line numbers and column offsets are not dumped by default. If this is wanted, include_attributes can be set to True.

ast.copy_location(new_node, old_node) Copy source location (lineno and col_offset) from old_node to new_node if possible, and return new_node.

_fields Each concrete class has an attribute _fields which gives the names of all child nodes. Each instance of a concrete class has one attribute for each child node, of the type as defined in the grammar. For example, ast.BinOp instances have an attribute left of type ast.expr. If these attributes are marked as optional in the grammar (using a question mark), the value might be None. If the attributes can have zero-or-more values (marked with an asterisk), the values are represented as Pyt

lineno col_offset Instances of ast.expr and ast.stmt subclasses have lineno and col_offset attributes. The lineno is the line number of source text (1-indexed so the first line is line 1) and the col_offset is the UTF-8 byte offset of the first token that generated the node. The UTF-8 offset is recorded because the parser uses UTF-8 internally.

col_offset Instances of ast.expr and ast.stmt subclasses have lineno and col_offset attributes. The lineno is the line number of source text (1-indexed so the first line is line 1) and the col_offset is the UTF-8 byte offset of the first token that generated the node. The UTF-8 offset is recorded because the parser uses UTF-8 internally.

class ast.AST This is the base of all AST node classes. The actual node classes are derived from the Parser/Python.asdl file, which is reproduced below. They are defined in the _ast C module and re-exported in ast. There is one class defined for each left-hand side symbol in the abstract grammar (for example, ast.stmt or ast.expr). In addition, there is one class defined for each constructor on the right-hand side; these classes inherit from the classes for the left-hand side trees. For exam

exception AssertionError Raised when an assert statement fails.

ascii(object) As repr(), return a string containing a printable representation of an object, but escape the non-ASCII characters in the string returned by repr() using \x, \u or \U escapes. This generates a string similar to that returned by repr() in Python 2.

array.typecodes A string with all available type codes.