hpPrime, with Python Syntax, beyond the Python numeric language
02-28-2019, 02:32 AM (This post was last modified: 05-20-2019 08:59 PM by compsystems.)
Post: #1 compsystems Senior Member Posts: 1,163 Joined: Dec 2013
hpPrime, with Python Syntax, beyond the Python numeric language
Hello, Xcas supports Python syntax, although much of it does not work the same as the Python language, since it is numeric and XCAS is numeric / symbolic
I am adapting a Python guide to Xcas with Python syntax, this document may have errors in writing, my native language is Spanish, any contribution is welcome

The hpprime supports Xcas with Python syntax, only within a program code, we hope that the development group of the hpprime includes the Xcas history engine with support for Python syntax

Thanks

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https://www-fourier.ujf-grenoble.fr/~par...casen.html

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3. AN INFORMAL INTRODUCTION TO XCAS WITH PYTHON SYNTAX

In the following examples, input and output are distinguished by lines, the entry value or sentence is located after of a numeral (xcas installer version), this can occupy one or several lines, output located on the next line.

1: 9-2 [enter] returns
7

the above means that on line number 1 the input is located and on the next line the output

python_compat(1) [enter] initializes the python syntax in xCAS and ** operator to calculate powers
python_compat(2) [enter] initializes the python syntax in xCAS and ** operator equal to Xor operator
python_compat(0) [enter] ends the python syntax in xCAS

The equal sign (=) is used to assign a value to a variable. Afterwards, only the result (right side evaluated) is displayed

Width = 20 [enter] returns 20
Height = 5 * 9 [enter] returns 45
Width * Height [enter] returns 900

Although it is recommended to use better : =, because the equal sign is used for the equations
Width := 20 [enter] returns 20

If a variable is not “defined”, maintains its symbolic value, unlike the python language, it returns a error message

var01 [enter] returns var01

Many of the examples in this manual, include comments. Comments start with the hash character, #, and extend to the end of each line. A comment may appear at the beginning of a line or after a sentence, but not within a string literal. A hash character within a string literal is just a hash character. Since comments are to clarify code and are not interpreted, they may be omitted when typing in examples.

Some examples:

value := 987; # this is a comment [enter] returns 987
txt1 := "# This is not a comment because it's inside quotes."; [enter] returns "# This is not a comment because it's inside quotes."

3.1. USING SYNTAX PYTHON AS A CALCULATOR
Let’s try some simple Xcas commands with syntax Python.

3.1.1. NUMBERS

A sequence of inputs, shows a sequence of outputs, each sentence must end in a semicolon.

2 + 2;
50 - 5*6;
(50 - 5*6) / 4;
8 / 5 # Unlike the python language, a division is not always evaluated to float, because it many times maintains its rational form.
[enter]
4, 20, 5, 8/5

The integer numbers (e.g. 2, 4, 20) have type integer or DOM_INT, the ones with a fractional part (e.g. 5.0, 1.6, 5.) have type 'real' or DOM_FLOAT. We will see more about object types later in the tutorial

Operators with mixed type operands (interger and floating) convert the result to floating point:

4 * 3.75 – 1 [enter] returns
14.0 # and not 14

In a division, an argument with a fractional value or ending with dot returns a float (e.g. 17/3.0 returns 5.66666666667). To do floor division and get an integer result (discarding any fractional result) you can use the // infix operator; to calculate the remainder you can use % infix operator:

17 / 3; # classic division
17 / 3.; # approximate value calculation
17 // 3; # floor division discards the fractional part
17 % 3; # the % operator returns the remainder of the division
5 * 3 + 2 # result * divisor + remainder
[enter] returns
17/3, 5.66666666667, 5, 2, 17

With python_compat(1), it is possible to use the ** operator to calculate powers

5 ** 2; # 5 squared
2 ** 7; # 2 to the power of 7
[enter] returns
25, 128

3.1.2. STRINGS

The strings require a character container, can be expressed between single quotes pair ('...') or double quotes pair ("..."), but Xcas uses the character ' to perform other operations, for this reason use best double quotes for strings

"Enter x value" [enter] prints only the content of the string, that is without the containers or ("...") quotes pair.
Enter x value # Although internally it is "Enter x value"

"doesn't" [enter] prints doesn't
double clicking on the string, shows the pair of quotes "doesn't"

This is not a string because it's not in quotation marks

Within the content of the strings also can be used to escape character:
\t tabulation
\n new line
\" double quotes

"This is the string in the first line\nand this is the second string in a second line\n\tand now a third tabulated" [enter] prints

This is the string in the first line
and this is the second string in a second line
↦ ↦ and now a third tabulated

To insert a double quote, within a string, the " character must be duplicated.
"Enter a ""String"":" [enter] prints
Enter a "String":

Or with escape quotes
"Enter a \"String\":" [enter] prints
Enter a "String":

If you want to show double quotes at the beginning, you should follow the next sequence "\"…\"" e.g.
"\"Enter a String:\"" [enter] prints
"Enter a String:"

"\"This is the string in the first line\nand this is the second string in a second line\n\tand now a third tabulated\"" [enter] prints

"This is the string in the first line
and this is the second string in a second line
and now a third tabulated"

Strings can be concatenated (glued together) with the + operator, and repeated with * operator:
For example to get: unununium (Element 111)

3 * "un" + "ium"# 3 times "un", followed by "ium" [enter] prints
unununium

Strings can be indexed (subscripted), with the first character having index 0. There is no separate character type; a character is simply a string of size one:

word := "Xcas" [enter] returns " Xcas "
word # character in position 0 [enter] prints
X
word # character in position 2 [enter] prints
s

Indices may also be negative numbers, to start counting from the right:
word[ -1 ] # last character [enter] prints
s
word[ -2 ] # second-last character [enter] prints
a
word[ -3 ] [enter] prints
c
word[ -4] [enter] prints
X

Note that since -0 is the same as 0, negative indices start from -1.
+---+---+---+---+
| X | c | a | s |
+---+---+---+---+
0__1__2__3
-4_-3_-2_-1

In addition to indexing, slicing is also supported. While indexing is used to obtain individual characters, slicing allows you to obtain substring:

word[1:3] # characters from position 1 (included) to 3 (excluded) [enter] prints
ca
word[0:2] # characters from position 0 (included) to 2 (excluded) [enter] prints
Xc

Slice indices have useful defaults; an omitted first index defaults to zero, an omitted second index defaults to the size of the string being sliced.

word[:2] # character from the beginning (position 0) to position 2 (excluded) [enter] prints
Xc
word[1:] # characters from position 1 (included) to the end (position 3) [enter] prints
cas
word[-3:] # characters from the second-last (included) to the end (position -1) [enter] prints
cas

Note string[start:end] how the start is always included, and the end always excluded. This makes sure that string[:end] + string[start:] is always equal to string

word[:1] + word[1:] [enter] prints
Xcas
word[:2] + word[2:] [enter] prints
Xcas

Attempting to use an index out of the maximum character size will result in an error:

word [enter] prints
s
word # the word only has 4 characters, between 0..3 [enter] returns
Gen [int] Error: Bad Argument Type

However, out of range slice indexes are handled gracefully when used for slicing:

word[1:5] [enter] prints
cas
word[5:] [enter] returns
""
word[0:1] + word[1:5] [enter] prints
Xcas

Creating string from another:

word[0:] + " with Python Syntax" [enter] returns
"Xcas with Python Syntax"

The built-in function len() returns the length of a string:
s := "supercalifragilisticexpialidocious" [enter] returns
len(s) 34

Unlike the Python language, where the elements or characters of a string are immutable, the elements or characters of a string in Xcas can be changed.
word [enter] returns
Xcas

word := "x"; word [enter] returns
Done, xcas

3.1.3. LIST

Xcas knows a number of compound data types, used to group together other values. The most versatile is the list, which can be written as a list of comma-separated values (items) between square brackets. Lists might contain items of different types, but usually the items all have the same type.

squares := [1, 4, 9, 16, 25] [enter] returns
[1, 4, 9, 16, 25]

squares # indexing in 0 returns the ítem [enter] returns
1
squares[-1] [enter] returns
25
squares[-3:] # slicing (-3 to -1) returns a new list [enter] returns
[9, 16, 25]

All slice operations return a new list containing the requested elements. This means that the following slice returns a new (shallow) copy of the list:

squares[:] [enter] returns
[1, 4, 9, 16, 25]

The lists are a mutable type, i.e. it is possible to change their content:
cubes := [1, 8, 27, 65, 125] # something's wrong here [enter] returns
[1, 8, 27, 65, 125]
4 ** 3 # the cube of 4 is 64, not 65! [enter] returns
64
cubes := 64 # replace the wrong value [enter] returns
cubes [enter] returns
[1, 8, 27, 64, 125]

Lists also support operations like concatenation, you can also add new items at the end of the list, by using the .append() method or . extend() for add other list at the end of the a list. the namevar.append() and namevar .extend() methods Automatically modify the value namevar

APPEND

cubes.append( 216 ) # add the cube of 6 [enter] returns
[ 1, 8, 27, 64, 125, 216 ]
cubes.append( 7 ** 3 ) # and the cube of 7 [enter] returns
[ 1, 8, 27, 64, 125, 216, 343 ]
cubes [enter] returns
[ 1, 8, 27, 64, 125, 216, 343 ]

l1=[1,2,3]
l2=[4,5,6]
l1.append(l2) [enter] returns
[1,2,3,[4,5,6]]

INSERT

cubes.insert( 0, 0 ) [enter] returns
[ 0, 1, 8, 27, 64, 125, 216, 343 ]

INDEX: Number of elements different from the maximum number of the index.
cubes.index(343) [enter] returns
7

cubes.length [enter] returns
8

You can insert in size + 1 position
cubes.insert( 7+1, 8**3 ) [enter] returns
[ 0, 1, 8, 27, 64, 125, 216, 343, 512 ]

IN (member or belonging to an element) the initial position starts at 1, 0 means it is not in the list

9**3 in cubes [enter] returns
0 (no position)

8**3 in cubes [enter] returns
9

cubes.index(8**3) [enter] returns
8

EXTEND (CONCATENATION)

squares [enter] returns
[ 1, 4, 9, 16, 25 ]
squares.extend( [ 36, 49, 64, 81, 100 ] ) [enter] returns
[ 1, 4, 9, 16, 25, 36, 49, 64, 81, 100 ]

l1=[1,2,3]
l2=[4,5,6]
l1.extend(l2) [enter] returns
[ 1, 2, 3, 4, 5, 6]

Unlike the Python language, list + list, Xcas does not perform concatenation, but depends on the type of list, it can be sum of vectors (sum of elements from left to right), or sum of polynomials (sum of elements from right to left)

# + as sum of vectors
[ 1, 4, 9, 16, 25 ] + [ 36, 49, 64, 81, 100 ] [enter] returns
[ 37, 53, 73, 97, 125 ]

[1,2,3]+ # equal to [1,2,3]+[4,0,0] [enter] returns
[5,2,3]

# sum of polynomials
poly1[1,2,3]+poly1 # equal to [1,2,3]+[0,0,4] [enter] returns
poly1[1,2,7]

special case:

a := ["a", "b", "c"];
n := [1, 2, 3] [enter]
a+n # concatenate element by element [enter]
["a1","b2","c3"]

#########
Assignment to slices is also possible, and this can even change the size of the list or clear it entirely:

Letters := [ "a", "b", "c", "d", "e", "f", "g" ] [enter] returns
[ "a","b","c","d","e","f","g" ]

Letters[ 2:5 ] [enter]
["c","d","e"]

# replace some values
Letters[ 2:5 ] := [ "C", "D", "E" ] [enter] returns
["a", "b", "C", "D", "E", "f", "g"]

SUPPRESS

# but now remove them
Letters[2:5] := [] [enter] Python language returns
[ "a", "b", "f", "g"]

suppress( Letters,2:5) [enter] Xcas Python Syntax returns
[ "a", "b", "f", "g"]

# clear the list by replacing all the elements with an empty list
Letters[ : ] = [] Python language returns
[ ]
suppress( Letters,:length(Letters)) [enter] Xcas Python Syntax returns
[ ]

REMOVE Remove all occurrences
L1:=[9,9,9,8,8,7,9,6]
L1.remove(9) [enter]
[8,8,7,6]

Letters.remove("a") [enter]
["b","c","d","e","f","g"]

POP
delete last item

Letters.pop [enter] returns "g"
Letters [enter] returns
["b","c","d","e","f"]

specifying a position
Letters.pop(3) [enter] "e"
Letters [enter] returns
["b","c","d","e","f"]

########
The built-in function len() also applies to lists:
Letters := [ "a", "b", "c", "d", "e", "f", "g" ];
len(letters) [enter] returns
7

########
It is possible to nest lists (create lists containing other lists), for example:
a := ["a", "b", "c"];
n := [1, 2, 3];
x := [a, n] [enter] returns
[["a","b","c"],[1,2,3]]

x [enter] returns
["a", "b", "c"]

x
[enter] returns
"b"

x[0,1] # alternative way, not available in python language
[enter] returns
"b"

3.2. First Steps Towards Programming

We will write an initial subsequence of the Fibonacci series as follows:

# Fibonacci series:
# the sum of two elements defines the next

ClrIO
a, b = 0, 1
while a < 10:
↦ ↦print(a)
↦ ↦a, b = b, a+b [enter] returns

0
1
1
2
3
5
8

Writing ...

LO SUFICIENTEMENTE BUENO ES ENEMIGO DE LA EXCELENCIA.
02-28-2019, 08:11 PM
Post: #2 Giancarlo Member Posts: 207 Joined: Dec 2013
RE: hpPrime with Python syntax
Hello Compsystems,
Thank you very much for writing this text.
May I ask you to write some complete examples with the full code to digit into the calculator?

I could be interested, one day or another to learn python, in particular if some other libraries will be implemented.

Thanks

Giancarlo
03-03-2019, 05:31 PM (This post was last modified: 05-18-2019 11:12 PM by compsystems.)
Post: #3 compsystems Senior Member Posts: 1,163 Joined: Dec 2013
RE: hpPrime with Python syntax, Beyond the Python language
Testing the previous examples in Xcas and hpprime, please copy the following code

PHP Code:
#cas
def testPythonSyntax():

local Done "Done"

ClrIO
python_compat
(1)

# this is a comment

print( # 4

print( 50 5*# 20

print( (50 5*6) / # 5

print( 5# 8/5

print( 3.75 # 14.0 and no 14

print( 17 # 17/3, rational division

print( 17 3. # 5.666..., approximate value calculation

print( 17 // 3  ) # 5, floor division discards the fractional part

print( 17 3  # 2, the % operator returns the remainder of the division

print( # 17, result * divisor + remainder

print( ** # 25, 5 squared

print( ** # 128, 2 to the power of 7

# Strings

print( "Enter x value" # prints only the content of the string

print( "It's not a python language, it's CAS + python syntax" )
print(
"This is the string in the first line\nand this is the second string in a second line\n\tand now a third tabulated" )
print(
"Enter a ""String"":" # to insert a double quote, within a string, the " character must be duplicated

print( "Enter a \"String\":" # or with escape quotes

print( "\"Enter a String:\"" # if you want to show double quotes at the beginning and end, you should follow the next sequence "\" … \"" e.g.

# Arithmetic operations in strings, sum or concatenation and multiplication by a scalar (constant)

print( "un" "ium" # 3 * "un" + "ium" # 3 times "un", followed by "ium"

word := "Xcas"

# The built-in function len() returns the length of a string:

print( lenword ) ) # 4 chars

print( "1__2__3__4" )
print(
"0__1__2__3" # pos 0...3

print( "+---+---+---+---+" )
print(
"| X | c | a | s |" )
print(
"+---+---+---+---+" )
print(
"-4_-3_-2_-1" # pos -1...-4

# Strings can be indexed. The first character on the left occupies the first positive position and starts at 0 and continues upward for the positions on the right. The first character on the right occupies the first negative position and starts at -1 and continues downwards for the positions on the left

print( word[:] ) # Xcas, print the entire string

print( word] ) # X, character in firts position

print( word] ) # s, character in position 3, base 0

print( word[ -] ) # s, last character

print( word[ -] ) # a, second-last character

print( word[ -] ) # X

# Strings can be indexed by slicing to get a new list
# Note string[  start  :  end  ] the start is always included, and the end always excluded.

print( word1:] ) # ca, characters from position 1 (included) to 3 (excluded)

# To select the first k characters (slice), stringName( [ 0 : k ] ) is used.

print( word0:] ) # Xc, characters from position 0 (included) to 2 (excluded)

# stringName[ k : ], portion from the index k to the end of the string

print( word1:] ) # cas, characters from position 1 (included) to the end (size of the string, position 3)

print( word[ -3:] ) # cas, characters from the third-last (included) to position -1

# stringName[ : k ], portion from the begin of the string to the index k-1

print( word[:] ) # Xca

print( word[:] + word1:] ) # Xcas, stringName[ : k ] + stringName[ k : ] = stringName[:]

print( word] ) # s
# Remove the following comment to verify the error
# print( word[ 4 ] ) # Error: the word only has 4 characters, between 0..3

print( word1:] ) # cas, in an interval values outside the size of the string are ignored

print( word5:] ) # prints ""

print( word0:] + word1:] ) # Xcas

print( word0:] + " with Python Syntax" # Xcas with Python Syntax

:= "supercalifragilisticexpialidocious"

print( len) ) # 34

word] := "x" # unlike the Python language, where the elements or characters of a string are immutable, the elements or characters of a string in Xcas can be changed.

print( word[:] )

# List

squares := [ 1491625 ]
print(
squares )

print(
squares] ) # indexing in 0 returns the firts ítem

print( squares[ -] )# 25

print( squares[ -3:] ) # slicing (-3 to -1) returns a new list [ 9, 16, 25 ]

# ...

return Done
#end

testPythonSyntax() [enter] returns

4
20
5
8/5
14.0
17/3
5.66666666667
5
2
17
25
128
Enter x value
It's not a python language, it's CAS + python syntax
This is the string in the first line
and this is the second string in a second line
and now a third tabulated
Enter a "String":
Enter a "String":
"Enter a String:"
unununium
4
1__2__3__4
0__1__2__3
+---+---+---+---+
| X | c | a | s |
+---+---+---+---+
-4_-3_-2_-1
Xcas
X
s
s
a
X
ca
Xc
cas
cas
Xca
Xcas
s
cas
""
Xcas
Xcas with Python Syntax
34
xcas
[1,4,9,16,25]
1
25
[9,16,25]

Sequences

t1:=("one", "two", "three")

"one" in t1 [enter] returns 1
"two" in t1 [enter] returns 2

t2:=("a","a","a","e","e","i","i","i","u") [enter]
t2.count(t2,"a") [enter] returns 1? > 3

t2.length [enter] returns 9

t3:=("XCAS",123,x+y)
str1, num1, symb1 := t3 [enter]
str1 [enter] "XCAS"
num1 [enter] 123
symb1 [enter] x+y

LO SUFICIENTEMENTE BUENO ES ENEMIGO DE LA EXCELENCIA.
03-05-2019, 12:23 PM
Post: #4 Giancarlo Member Posts: 207 Joined: Dec 2013
RE: hpPrime with Python syntax, Beyond the Python language
Hello compsystems,
Thank you very much. That complete your post in my opinion. I will try it in the next days.

Thanks again,

Giancarlo
03-08-2019, 02:35 AM (This post was last modified: 05-21-2019 11:19 PM by compsystems.)
Post: #5 compsystems Senior Member Posts: 1,163 Joined: Dec 2013
RE: hpPrime, with Python Syntax, beyond the Python numeric language
List comprehension.

Is a compact expression to define lists.

# Case 1, define a numerical sequence
list1 := range( 5 ) # The "range" function returns a list, starting at 0 and ending with the indicated number minus one, increase in 1
[enter] returns
[ 0, 1, 2, 3, 4 ]
range( 5 ) is equivalent to [ seq( 0..4 ) ]

list1a := range( 1, 5 ) # specifying start and end-1
[enter] returns
[ 1, 2, 3, 4]
range( 1, 5 ) is equivalent to [ seq( 1..4 ) ]

list1b := range( 1, 8, 1.9 ) # specifying start and end-1, more step
[enter] returns
[ 1.0, 2.9, 4.8, 6.7 ]
range( 1, 8, 1.9 ) is equivalent to [ seq( 1..7, 1.9 ) ]

range( 11, 1, -1) # negative ranges [enter] returns
[ 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 ]

range( 11, 1, -1) is equivalent to [ seq( 11..2, -1 ) ]

# Case 2, define a list, with an input function
list2 := [ k*k for k in range( 5 ) ] # create a list, for each element in the range, multiply it by itself, and add it as a new item in the list
[enter] returns
[ 0, 1, 4, 9, 16 ]

[ k*k for k in range( 5 ) ] is equivalent to seq( j*j, j, 0, 4 ) # variable and domain separately
or seq( j*j, j, [ 0, 1, 2, 3, 4 ] ) # explicit domain as a list
or [ seq( j*j, j=0..4 ) ] # domain as an expression

# Case 3, define list with a symbolic sequence
list2 := [ x^j for j in range( 4 ) ] [enter] returns
[ 1, x, x^2, x^3 ]

[ x^j for j in range( 4 ) ] is equivalent to seq( x^j, j, 0, 3 )

# Case 3a, define list with a symbolic constant
list3a := [ t for c in range( 4 ) ] [enter] returns
[ t, t, t, t ]
[ t for c in range( 4 ) ] is equivalent to seq( t, 4 )

# Case 3b, define list with a numeric constant
list3b := [ -1 for c in range( 4 ) ] [enter] returns
[ -1, -1, -1, -1 ]
[ 1 for c in range( 4 ) ] is equivalent to seq( -1, 4 )

# Case 4, define a list of list (matrix)
list4 := [ [ k, k + 2 ] for k in range ( 5 ) ] [enter] returns
[[ 0,2 ],[ 1,3 ],[ 2,4 ],[ 3,5 ],[ 4,6 ]]

[ [k, k + 2] for k in range ( 5 ) ] is equivalent to seq( [ k, k + 2 ], k, 0, 4 ), or
[ seq( [ k, k + 2 ], k=0..4 ) ]

PHP Code:
#cas
def testPythonSyntax_part2():

local Done "Done"

ClrIODispG
python_compat
(1)

# Case 1, define a numerical sequence

list1 := range# The "range" function returns a list, starting at 0 and ending with the indicated number minus one, increase in 1

print ( list1 )
print ( [
seq0..4 ) ] ) # equivalent function

print ( "" )

list1a := range1# specifying start and end-1

print ( list1a )
print ( [
seq1..4 ) ] ) # equivalent function

print ( "" )

list1b := range181.9 # specifying start and end-1, more step

print ( list1b )
print ( [
seq1..71.9 ) ] ) # equivalent function

print ( "" )

list1c := range111, -1# negative ranges

print ( list1c )
print ( [
seq11..2, -) ] ) # equivalent function

print ( "" )

# Case 2, define a list, with an input function

list2 := [ k*for k in range) ] # create a list, for each element in the range, multiply it by itself, and add it as a new item in the list

print ( list2

# equivalent functions

print ( seqj*jj0) ) # variable and domain separately

print ( seqj*jj, [ 0123] ) ) # explicit domain as a list

print ( [ seqj*jj=0..4 ) ] ) # domain as an expression

print ( "" )

# Case 3, define list with a symbolic sequence

list3 := [ x^for j in range) ]
print (
list3 )
print (
seqx^jj0) ) # equivalent function

printf seqx^jj0) ) # impresion mathbook

print ( "" )

# Case 3a, define list with a symbolic constant

list3a := [ for c in range) ]
print (
list3a )
print (
seqt) ) # equivalent function

print ( "" )

# Case 3b, define list with a numeric constant

list3b := [ -for c in range) ]
print (
list3b )
print (
seq( -1) ) # equivalent function

print ( "" )

# Case 4, define a list of list (matrix)

list4 := [ [ k] for k in range ) ]
print (
list4 )
print (
seq( [ k], k0) ) # equivalent function

printf seq( [ k], k0) )

return
Done
#end

testPythonSyntax_part2() [enter] returns

[0,1,2,3,4]
[0,1,2,3,4]

[1,2,3,4]
[1,2,3,4]

[1.0,2.9,4.8,6.7]
[1,2.9,4.8,6.7]

[11,10,9,8,7,6,5,4,3,2]
[11,10,9,8,7,6,5,4,3,2]

[0,1,4,9,16]
[0,1,4,9,16]
[0,1,4,9,16]
[0,1,4,9,16]

[1,x,x**2,x**3]
[1,x,x**2,x**3]

[t,t,t,t]
[t,t,t,t]

[-1,-1,-1,-1]
[-1,-1,-1,-1]

[[0,2],[1,3],[2,4],[3,5],[4,6]]
[[0,2],[1,3],[2,4],[3,5],[4,6]]

#################################

Functions

Functions are defined with the keyword def, followed by the name of the function and its parameters in (). Another way to define functions is with the keyword lambda (only for an expression).
The value returned in the functions with def will be the one given with the return statement.

using def:

PHP Code:
def sumxy(x2):
⇥⇥return x # Return the sum of the value of the variable "x" and the value of "y"
[enter] returns
"Done"
Above function name is sumxy, it expects two arguments x and/or y and returns their sum.

# Call the function
sumxy(4) # The variable "y" takes the default value: 2 [enter] returns
6

sumxy(4, 10) # The variable "y" takes the value entered: 10 [enter] returns
14

Let’s see how we can convert the above function into a lambda function:

PHP Code:
sumxy lambda xy=2

sumxy(4) [enter] returns
6
sumxy(4, 10) [enter] returns
14

PHP Code:
#cas
def sumxy(x2):
⇥⇥return x y
#end

If we check type of add, it is a function.
type(sumxy) [enter] returns func

The functions can be passed as parameters to a new function which expects a function name as parameter like map cmd

def multiply2(x):
return x * 2

map(pow2, [1, 2, 3, 4]) [enter] returns [1,4,9,16]

#############

Another example

PHP Code:
#cas
def calculatoropera):
⇥⇥if "addition" == oper:
⇥⇥⇥⇥return a b
⇥⇥elif
"subtraction" == oper:
⇥⇥⇥⇥return a b
⇥⇥elif
"multiplication" == oper:
⇥⇥⇥⇥return a b
⇥⇥elif
"division" == oper:
⇥⇥⇥⇥return a b
⇥⇥else
:
⇥⇥⇥⇥return None
#end

calculator( "addition", 3, 4 ) [enter] returns 7
calculator( "subtraction", 3, 4 ) [enter] returns -1
calculator( "multiplication", 3, 4 ) [enter] returns 12
calculator( "division", 3, 4 ) [enter] returns 3/4~=0.75

to rewrite the code use python(name of the program)

python( calculator ) [enter] returns
"lambda op_rep,a,b:
return(a+b)
else :

if ((""subtraction"")==op_rep) :
return(a-b)
else :

if ((""multiplication"")==op_rep) :
return(a*b)
else :

if ((""division"")==op_rep) :
return(a/b)
else :
return(None)"

###########

ZIP

vector1 = [1,2,3,4]
vector2 = [7,8,3,2]
DispG
ClrIO
printf("vector1 vector2")
for array2d in zip(vector1,vector2):
printf("%gen \t %gen", array2d, array2d)

vector1 := [1,2,3,4];
vector2 := [7,8,3,2]

dict1 = table(zip(vector1,vector2))

all(iterable)
Return True if in evaluating all elements of the iterable list/string are true (or if the iterable is empty). If not, it returns False.

all function equivalent to:

#cas
def all( iterable ):
for element_ in iterable:
if not element_:
return False
return True
#end

True - If all elements in an iterable are true
False - If any element in an iterable is false

Truth table for all()
When ----------------------------------- Return Value
All values are true -------------------- True
All values are false ------------------- False
One value is true (others are false) --- False
One value is false (others are true) --- False
Empty Iterable ------------------------- True

# Examples for list

# all values true

lst1 := [ -5.8, -1, 1, 3.5, 4, 10 ];
print( all( lst1 ) )
When executing the program, the output on the I/O line will be:
1
and in the console will be:
True

# all values false

lst1 = [ 0, False, 0=-1 ]
;
print( all( lst1 ) )

[enter] returns
1
False

# one false value

lst1 := [-1, 1, 0, abs(-1)==1 ]
;
print( all( lst1 ) )

[enter] returns
1
False

# one true value

lst1 := [ 0, False, abs(-1)==1 ]
;
print( all( lst1 ) )

[enter] returns
1
False

# empty iterable

lst1 = []
;
print( all( lst1 ) )

[enter] returns
1
True

lst1:= [ 1, True, "×÷" ]
print( all( lst1 ) )

[enter]
Error, can not be determined if the element "×÷" is true or false

# Examples on strings (NOT SUPPORTED)

str1 := "This is string";
print( all( str1 ) )
[enter] returns Error

# Examples on tables

In case of tables data, if all the left part are numeric and true or the table is empty, all() returns True. Else, it returns false for all other cases..

tbl1 := table( 0: "", 65: "A", 97: "a", 215: "×", 247: "÷" );
print( all( tbl1 ) )

[enter]
returns
1
Print
False

tbl1 := table( 65: "A", 97: "a", 215: "×", 247: "÷" );
print( all( tbl1 ) )

[enter]
returns
1
Print
True

tbl1 := table()
print( all( tbl1 ) )

[enter]
returns
1
Print
True

tbl1 := table("1": one, "2": two)

tbl1 := table("65": "A", "97": "a")

tbl1 := { -1: False, 0: False };
print( all( tbl1 ) )

[enter] returns 1
Print False

tbl1 := { -1: True, 1: True };
print( all( tbl1 ) )

[enter] returns 1
True

s = {"000": 'True'}

print(all(s))
Error

lst1= [ 1, True, "×÷" ]
print( all( lst1 ) )

LO SUFICIENTEMENTE BUENO ES ENEMIGO DE LA EXCELENCIA.
04-04-2019, 01:33 AM (This post was last modified: 04-27-2019 02:09 AM by compsystems.)
Post: #6 compsystems Senior Member Posts: 1,163 Joined: Dec 2013
RE: hpPrime, with Python Syntax, beyond the Python numeric language
print() function (Now accept extra parameters)

Definition and Usage

The print() function prints the specified message to the console screen

Syntax for a only object:
print( object )

Example
print("Hello world")[enter] prints Hello world

Syntax for more than one object, The objects are printed by default, separated by commas
print( object(s) )

Example
print("Hello", "world") [enter] prints Hello,world

optional parameters
print( object(s), sep="string sepator", end="string end")

separator="string sepator": Specify how to separate the objects, if there is more than one. Default is ","

Example
print("Hello", "world", sep=" ") [enter] prints Hello world
print("Hello", "world", sep="_") [enter] prints Hello_world
print("Hello", "world", sep=";") [enter] prints Hello;world
print("Hello", "world", sep="\n") [enter] prints
Hello
world

end/endl="string end"
Specify what to print at the end. Default is '\n' (line feed)

PHP Code:
#cas
def fib(n):  # write Fibonacci series up to n Print a Fibonacci series up to n

a01

while n:
print(
aendl="\t"  )

aba+b

return Done
#end

fib(22) [enter] prints
PHP Code:
0    1    1    2    3    5    8    13    21

PHP Code:
#cas
def fib(n):  # write Fibonacci series up to n Print a Fibonacci series up to n

a01

while n:
print(
aendl="\n"  )

aba+b

return Done
#end

fib(22) [enter] prints
PHP Code:
0
1
1
2
3
5
8
13

PHP Code:
#cas
def legendre_nevalX="" ):

local pxxtype2argpurge(x)
if
getType(n) == "NUM":

px := 1/(2^n*n!)*diff((x^2-1)^n,x,n)

type2arg := getType(evalX)
if
type2arg == "NUM" or type2arg == "EXPR" or type2arg == "VAR":

px := subst(px,x=evalX)

elif type2arg == "STR" and evalX=="list":

px:=e2r(px)
return
px

return "Error, se espera un numero entero en el primer argumento"
#end

Nested List Comprehensions

Consider the following example of a 3x3 matrix held as a list containing three lists, one list per row:

m := [
[1, 2, 3],
[4, 5, 6],
[7, 8, 9]
]

Now, if you wanted to swap rows and columns, you could use a list comprehension:

Xcas Syntax Python
PHP Code:
[ [row_[col_] for row_ in m ] for col_ in seq(k,k,0,colDim(m)-1) ]
[enter] returns
[[1,4,7],[2,5,8],[3,6,9]]
To avoid apprehension when nesting list comprehensions, read from right to left.

A more verbose version of this snippet shows the flow explicitly:

Xcas Code
PHP Code:
transpose_(m):={

local col_row_mt;

mt := makemat(rowDim(m),colDim(m));
for
col_ from 0 to colDim(m)-do
for
row_ from 0 to rowDim(m)-do

mt[col_,row_] := m[row_,col_];

end_for
end_for

return mt;
}:;

transpose_([[1,2,3],[4,5,6],[7,8,9]]) [enter] returns
[[1,4,7],[2,5,8],[3,6,9]]

for i in [0, 1, 2]:
for row in mat:
print(row[i], end="")
print()

#####################
LOOPS

There are several types of loops in Xcas, FOR and WHILE. more for and while in python syntax

The "for" loop
For loops iterate over a given input sequence . Here is an script example:

ClrIO
PHP Code:
primes = 
for
prime in primes:
print(
primeendl=" "
[enter]

returns 0,[2, 3, 5, 7], 0, 0
print on console
2 3 5 7

For loops can iterate over a sequence of numbers using the "range" function. The range function returns a new list with numbers of that specified range. Note that the range function is zero based.

PHP Code:
ClrIO
# Prints out the numbers 0 1 2 3 4
for x in range(5):
print(
xendl=" ")
print(
"")

# Prints out 3 4 5
for x in range(36):
print(
xendl=" ")
print(
"")

# Prints out 3 5 7
for x in range(382):
print(
xendl=" "
[enter]

prints
0 1 2 3 4
3 4 5
3 5 7

"While" loops repeat as long as a certain boolean condition is met. For example:

PHP Code:
# Prints out 0 1 2 3 4
count_ := 0
while( count_ 5):
print(
count_endl=" ")

count_ += 1

"count value reached=" count_
[enter]

returns 0,"count value reached=5"
print on console
0 1 2 3 4

Break is used to exit a for loop or a while loop, whereas continue is used to skip the current block, and return to the "for" or "while" statement. A few examples:

PHP Code:
# Prints out 0 1 2 3 4
count_ := 0
while True:
print(
count_endl=" ")

count_ += 1

if count_ >= 5:
break
[enter]

returns 0,"count value reached=5"
print on console
0 1 2 3 4

PHP Code:
# Prints out only odd numbers 1 3 5 7 9
for x in range(10):

# Check if x is even

if == 0:
continue
print(
xendl=" "

[enter]

returns 1
print on console
1 3 5 7 9

LO SUFICIENTEMENTE BUENO ES ENEMIGO DE LA EXCELENCIA.
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