Hi, While getting through the ufunc documentation, (http://docs.scipy.org/numpy/docs/numpy-docs/reference/ufuncs.rst/) I took the liberty to change one line in the code segment which generates the "can cast safely" table. I wanted to increase the readability if the table by increasing its contrast. To this end, I replaced the character '0' by '-'. (I copy pasted the result below). Now two questions : 1) One thing is that some of you may not like this change and I'm fine with that because this was just for fun ! 2) A slightly more important thing is to double check that the table content is unchanged. Indeed, the table caption says it was generated on a 32 bits machine while my computer is running a 64 bits Linux. I believe that the table I generated was the same, but please make sure I didn't mess up something. Best, Pierre Quick preview of the change : the "can cast safely" table before : X ? b h i l q p B H I L Q P e f d g F D G S U V O M m ? 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 b 0 1 1 1 1 1 1 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 0 0 h 0 0 1 1 1 1 1 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 0 0 i 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 1 1 0 1 1 1 1 1 1 0 0 l 0 0 0 0 1 1 1 0 0 0 0 0 0 0 0 1 1 0 1 1 1 1 1 1 0 0 q 0 0 0 0 1 1 1 0 0 0 0 0 0 0 0 1 1 0 1 1 1 1 1 1 0 0 p 0 0 0 0 1 1 1 0 0 0 0 0 0 0 0 1 1 0 1 1 1 1 1 1 0 0 B 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 H 0 0 0 1 1 1 1 0 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 1 0 0 I 0 0 0 0 1 1 1 0 0 1 1 1 1 0 0 1 1 0 1 1 1 1 1 1 0 0 L 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 1 1 0 1 1 1 1 1 1 0 0 Q 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 1 1 0 1 1 1 1 1 1 0 0 P 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 1 1 0 1 1 1 1 1 1 0 0 e 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 0 0 f 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 0 0 d 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 1 1 1 1 1 1 0 0 g 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 1 1 1 1 0 0 F 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 0 0 D 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 G 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 0 0 S 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 0 0 U 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 V 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 M 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 m 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 the "can cast safely" table after : X ? b h i l q p B H I L Q P e f d g F D G S U V O M m ? 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 b - 1 1 1 1 1 1 - - - - - - 1 1 1 1 1 1 1 1 1 1 1 - - h - - 1 1 1 1 1 - - - - - - - 1 1 1 1 1 1 1 1 1 1 - - i - - - 1 1 1 1 - - - - - - - - 1 1 - 1 1 1 1 1 1 - - l - - - - 1 1 1 - - - - - - - - 1 1 - 1 1 1 1 1 1 - - q - - - - 1 1 1 - - - - - - - - 1 1 - 1 1 1 1 1 1 - - p - - - - 1 1 1 - - - - - - - - 1 1 - 1 1 1 1 1 1 - - B - - 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 - - H - - - 1 1 1 1 - 1 1 1 1 1 - 1 1 1 1 1 1 1 1 1 1 - - I - - - - 1 1 1 - - 1 1 1 1 - - 1 1 - 1 1 1 1 1 1 - - L - - - - - - - - - - 1 1 1 - - 1 1 - 1 1 1 1 1 1 - - Q - - - - - - - - - - 1 1 1 - - 1 1 - 1 1 1 1 1 1 - - P - - - - - - - - - - 1 1 1 - - 1 1 - 1 1 1 1 1 1 - - e - - - - - - - - - - - - - 1 1 1 1 1 1 1 1 1 1 1 - - f - - - - - - - - - - - - - - 1 1 1 1 1 1 1 1 1 1 - - d - - - - - - - - - - - - - - - 1 1 - 1 1 1 1 1 1 - - g - - - - - - - - - - - - - - - - 1 - - 1 1 1 1 1 - - F - - - - - - - - - - - - - - - - - 1 1 1 1 1 1 1 - - D - - - - - - - - - - - - - - - - - - 1 1 1 1 1 1 - - G - - - - - - - - - - - - - - - - - - - 1 1 1 1 1 - - S - - - - - - - - - - - - - - - - - - - - 1 1 1 1 - - U - - - - - - - - - - - - - - - - - - - - - 1 1 1 - - V - - - - - - - - - - - - - - - - - - - - - - 1 1 - - O - - - - - - - - - - - - - - - - - - - - - - 1 1 - - M - - - - - - - - - - - - - - - - - - - - - - - - 1 - m - - - - - - - - - - - - - - - - - - - - - - - - - 1