Words to remember VI

counter	A variable used to count something, usually initialized to zero and then incremented.
Empty string	A string with no characters and length 0, represented by two quotation marks.
Format operator	An operator, %, that takes a format string and a tuple and generates a string that includes the elements of the tuple formatted as specified by the format string.
Format sequence	A sequence of characters in a format string, like %d, that specifies how a value should be formatted.
Format string	A string, used with the format operator, that contains format sequences.
Flag	A boolean variable used to indicate whether a condition is true.
Invocation	A statement that calls a method.
Immutable	The property of a sequence whose items cannot be assigned.
Index	An integer value used to select an item in a sequence, such as a character in a string.
Item	One of the values in a sequence.
Method	A function that is associated with an object and called using dot notation.
Object	Something a variable can refer to. For now, you can use “object” and “value” interchangeably.
Search	A pattern of traversal that stops when it finds what it is looking for.
Sequence	An ordered set; that is, a set of values where each value is identified by an integer index.
Slice	A part of a string specified by a range of indices.
Traverse	To iterate through the items in a sequence, performing a similar operation on each