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⇤ ← Revision 20 as of 2008-11-17 14:13:28 →
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Editor: KorFreier
Comment:
← Revision 25 as of 2008-11-17 14:23:55 → ⇥
Size: 2538
Editor: KorFreier
Comment:
Deletions are marked like this. Additions are marked like this.
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{{{
#!python
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{{{#!python
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1 1 
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Solution:

In [51]: a='0'
In [52]: b='1'
In [53]: 4*a+4*b

Out[53]: '00001111'
-----

In [44]: a=0,1,2,3

In [45]: a*4

Out[45]: (0,1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0)

Second Solution (in einer Schleife):
 Solution (two in one ;-):
{{{#!python
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for item in a:<br>
         b = item * 4 <br>
         b.sort()<br>
         c = item * 4<br>
         d = [b,c]<br>
         print d <br>

 for item in a:
         b = item * 4
         b.sort()
         c = item * 4
         d = [b,c]
         print d
}}}
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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.
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{{{
#!python
 {{{#!python
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{{{
#!python
 {{{#!python
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 * Display the elements {{{3:6}}} of arrays {{{B}}}  * Display the elements {{{3:6}}} of arrays {{{B}}} 
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 * Insert a new key-values pair {{{C:array(range(0,10,-1))}}} into {{{D}}}  * Insert a new key-values pair {{{C:array(range(0,10,-1))}}} into {{{D}}} 
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For loops

a)

   1 for i in range(0,4,1):
   2      print i
   3   
   4 0
   5 1 
   6 2
   7 3

  • Insert an expression in ... to get the results.

Solution:

b)

0 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
  • What are the corresponding loops?

Solution (two in one ;-): 

   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:

LehreWiki: Python/Exercise2 (last edited 2008-11-17 14:23:55 by KorFreier)