.. _python_strings: ============================================================= Python strings ============================================================= See this `List of methods applicable to strings `_ String formatting ----------------- Often you want to construct a string that incorporates the values of some variables. This can be done using the form *format % values* where *format* is a string that describes the desired format and *values* is a single value or tuple of values that go into various slots in the format. See `String Formatting Operations `_ This is best learned from some examples:: >>> x = 45.6 >>> s = "The value of x is %s" % x >>> s 'The value of x is 45.6' The *%s* in the format string means to convert x to a string and insert into the format. It will use as few spaces as possible. >>> s = "The value of x is %21.14e" % x >>> s 'The value of x is 4.56000000000000e+01' In the case above, exponential notation is used with 14 digits to the right of the decimal point, put into a field of 21 digits total. (You need at least 7 extra characters to leave room for a possible minus sign as well as the first digit, the decimal point, and the exponent such as *e+01*. >>> y = -0.324876 >>> s = "Now x is %8.3f and y is %8.3f" % (x,y) >>> s 'Now x is 45.600 and y is -0.325' In this example, fixed notation is used instead of scientific notation, with 3 digits to the right of the decimal point, in a field 8 characters wide. Note that *y* has been rounded. In the last example, two variables are inserted into the format string. Further reading --------------- See also: * ``_ * `List of methods applicable to strings `_ * `Input and Output documentation `_