Differences between revisions 21 and 24 (spanning 3 versions)

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)

What are the corresponding loops?

Solution:

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 21 as of 2008-11-17 14:16:01 → 
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+   ← Revision 24 as of 2008-11-17 14:21:10 → ⇥
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#!python
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-In [51]: a='0'
In [52]: b='1'
In [53]: 4*a+4*b
+= Data types =
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-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):

a = [range(0,4)]

for item in a:

         b = item * 4 

         b.sort() 

         c = item * 4 


         d = [b,c] 

         print d  





= Data types =
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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
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  * 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}}}
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