Differences between revisions 1 and 23 (spanning 22 versions)

For loops

a)

   1 a = [range(0,4)]
   2 for item in a:
   3          b = item * 4  
   4          b.sort() 
   5          c = item * 4 
   6          d = [b,c] 
   7          print d

Data types

A=dict([('a',1),('b',2)])

Please specify the data types:

A is a ...
'a' is a ...
1 is a ...
('a',1) is a ...
[('a',1),('b',2)] is a ...

Provide an alternative way to assign A

Scipy numeric types

from scipy import *

One byte consists of eight bit and covers the value range of 0..255 (uint8, unsigned integer) or -128..127.

   1 b=int8(128)
   2 -128 # Invalid range
   3 
   4 b.nbytes
   5 1

a)

What is the value range of the following types and how many bytes are allocated in the memory?

bool8
uint8, int8
uint16, int16
uint32, int32
uint64, uint64

Solution:

b)

How many bytes are allocated in the memory by these floating point types?

float32, float64, float96
complex64, complex128, complex192

Solution:

Data structures

a)

   1 D={'A':array(range(10)),'B':array(range(10))+1}

Which keys contains the dictionary D
Get the keys with the method D.keys()
Display all values of D using the method .values()
Display array A
Display the elements 3:6 of arrays B
Set this elements to 0
Insert a new key-values pair C:array(range(0,10,-1)) into D

Solution:

Reading and practicing

Install python and ipython on your computer and read through the tutorial which comes with the documentation. There are translations in other languages:

-  ⇤ ← Revision 1 as of 2008-10-30 09:31:30 → 
  Size: 1935
  Editor: anonymous
  Comment:
+   ← Revision 23 as of 2008-11-17 14:18:48 → ⇥
  Size: 2207
  Editor: anonymous
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
 Line 5:
+= For loops =
== a) ==
-Line 7:
+Line 9:
-= For loops =

== a) ==
-Line 12:
+Line 10:
-for ...:
     print i
  
0
1 
2
3
+a = [range(0,4)]
for item in a:
         b = item * 4  
         b.sort() 
         c = item * 4 
         d = [b,c] 
         print d
-Line 21:
+Line 19:
- * Insert an expression in {{{...}}} to get the results.

[[/Solution1A|Solution]]

== b) ==

{{{#!python
for ... in zip(range(0,4,1),range(4,0,-1)):
     print i,j
  
0 4
1 3
2 2
3 1
}}}

 * Insert an expression in {{{...}}} to get the results.

[[/Solution1B|Solution]]
-Line 42:
+Line 21:
-== c) ==
+= Data types =
-Line 44:
+Line 24:
-0
0 1
0 2
0 3
1 0
1 1
1 2
1 3
2 0
2 1
2 2
2 3
3 0
3 1
3 2
3 3
+A=dict([('a',1),('b',2)])
-Line 61:
+Line 26:
+Please specify the data types:
-Line 62:
+Line 28:
- * What are the corresponding loops?
+ * A is a ...
 * 'a' is a ...
 * 1 is a ...
 * ('a',1) is a ...
 * [('a',1),('b',2)] is a ...
-Line 64:
+Line 34:
-[[/Solution1C|Solution]]
+Provide an alternative way to assign A
-Line 68:
+Line 37:
-Line 71:
+Line 39:
-One byte consists of eight bit and covers the value range of 0..255 ({{{uint8}}}, unsigned integer) 
or -128..127.
+One byte consists of eight bit and covers the value range of 0..255 ({{{uint8}}}, unsigned integer)  or -128..127.
-Line 74:
+Line 41:
-{{{#!python
+{{{
#!python
-Line 81:
+Line 50:
-Line 83:
+Line 51:
-Line 92:
+Line 59:
-[[/Solution2A|Solution]]
+Solution:
-Line 97:
+Line 62:
-Line 103:
+Line 67:
-[[/Solution2B|Solution]]
+Solution:
-Line 107:
+Line 71:
-[[/Solution3A|Solution]]
+{{{
#!python
-Line 109:
+Line 74:
-== b) ==
{{{#!python
-Line 113:
+Line 76:
-Line 116:
+Line 78:
+ * Display all values of {{{D}}} using the method {{{.values()}}}
-Line 117:
+Line 80:
  * Display the elements {{{3:6}}} of arrays {{{B}}}
-Line 119:
+Line 82:
- * Insert a new key-values pair {{{C:array(range(0,10,-1))}}} into {{{D}}}   * Display all values of {{{D}}} using the method {{{.values()}}}
+ * Insert a new key-values pair {{{C:array(range(0,10,-1))}}} into {{{D}}}
-Line 122:
+Line 84:
-[[/Solution3B|Solution]]
+Solution:

= Reading and practicing =
Install python and ipython on your computer and read through the tutorial which comes with the documentation. There are translations in other languages:

 * [[http://wiki.python.org/moin/Languages/German?highlight=(CategoryLanguage)|German Language]]
 * [[http://starship.python.net/crew/gherman/publications/tut-de/online/tut/|Das Python-Tutorium (Version 1.5.2)]]
 * [[http://www.heise.de/ix/artikel/1999/11/184/|Beschränkung aufs Wesentliche (iX 11/1999)]]