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author | Tim Peters <tim.peters@gmail.com> | 2001-05-22 06:54:14 (GMT) |
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committer | Tim Peters <tim.peters@gmail.com> | 2001-05-22 06:54:14 (GMT) |
commit | bd695a716da3a532ebf0f3c32dd9d35d59de211e (patch) | |
tree | c2f1a5a1f7233c7dd615ce2d4d33feb8c336124a /Doc/tut/tut.tex | |
parent | 0ba9e3ac27d814bde97bbec212a4877e73d59c64 (diff) | |
download | cpython-bd695a716da3a532ebf0f3c32dd9d35d59de211e.zip cpython-bd695a716da3a532ebf0f3c32dd9d35d59de211e.tar.gz cpython-bd695a716da3a532ebf0f3c32dd9d35d59de211e.tar.bz2 |
Changed all the examples with ugly platform-dependent float output to use
numbers that display nicely after repr(). From much doctest experience
with the same trick, I believe people find examples with simple fractions
easier to understand too: they can usually check the results in their
head, and so feel confident about what they're seeing. Not even I get a
warm feeling from a result that looks like 70330.345024097141 ...
Diffstat (limited to 'Doc/tut/tut.tex')
-rw-r--r-- | Doc/tut/tut.tex | 36 |
1 files changed, 20 insertions, 16 deletions
diff --git a/Doc/tut/tut.tex b/Doc/tut/tut.tex index e71eac9..8fe90c4 100644 --- a/Doc/tut/tut.tex +++ b/Doc/tut/tut.tex @@ -426,8 +426,8 @@ There is full support for floating point; operators with mixed type operands convert the integer operand to floating point: \begin{verbatim} ->>> 4 * 2.5 / 3.3 -3.0303030303030303 +>>> 3 * 3.75 / 1.5 +7.5 >>> 7.0 / 2 3.5 \end{verbatim} @@ -469,15 +469,18 @@ complex number to a real number. Use \code{abs(\var{z})} to get its magnitude (as a float) or \code{z.real} to get its real part. \begin{verbatim} ->>> a=1.5+0.5j +>>> a=3.0+4.0j >>> float(a) Traceback (most recent call last): File "<stdin>", line 1, in ? TypeError: can't convert complex to float; use e.g. abs(z) >>> a.real -1.5 ->>> abs(a) -1.5811388300841898 +3.0 +>>> a.imag +4.0 +>>> abs(a) # sqrt(a.real**2 + a.imag**2) +5.0 +>>> \end{verbatim} In interactive mode, the last printed expression is assigned to the @@ -486,14 +489,15 @@ desk calculator, it is somewhat easier to continue calculations, for example: \begin{verbatim} ->>> tax = 17.5 / 100 ->>> price = 3.50 +>>> tax = 12.5 / 100 +>>> price = 100.50 >>> price * tax -0.61249999999999993 +12.5625 >>> price + _ -4.1124999999999998 +113.0625 >>> round(_, 2) -4.1100000000000003 +113.06 +>>> \end{verbatim} This variable should be treated as read-only by the user. Don't @@ -2609,16 +2613,16 @@ the \function{repr()} function, or just write the value between reverse quotes (\code{``}). Some examples: \begin{verbatim} ->>> x = 10 * 3.14 +>>> x = 10 * 3.25 >>> y = 200 * 200 >>> s = 'The value of x is ' + `x` + ', and y is ' + `y` + '...' >>> print s -The value of x is 31.400000000000002, and y is 40000... +The value of x is 32.5, and y is 40000... >>> # Reverse quotes work on other types besides numbers: ... p = [x, y] >>> ps = repr(p) >>> ps -'[31.400000000000002, 40000]' +'[32.5, 40000]' >>> # Converting a string adds string quotes and backslashes: ... hello = 'hello, world\n' >>> hellos = `hello` @@ -2626,7 +2630,7 @@ The value of x is 31.400000000000002, and y is 40000... 'hello, world\n' >>> # The argument of reverse quotes may be a tuple: ... `x, y, ('spam', 'eggs')` -"(31.400000000000002, 40000, ('spam', 'eggs'))" +"(32.5, 40000, ('spam', 'eggs'))" \end{verbatim} Here are two ways to write a table of squares and cubes: @@ -3477,7 +3481,7 @@ example, ... self.r = realpart ... self.i = imagpart ... ->>> x = Complex(3.0,-4.5) +>>> x = Complex(3.0, -4.5) >>> x.r, x.i (3.0, -4.5) \end{verbatim} |