hpPrime, with Python Syntax, beyond the Python numeric language

[compsystems]

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 
        a, b = 0, 1
        while a < n:
            print(a, endl="\t"  )
            a, b = b, a+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 
        a, b = 0, 1
        while a < n:
            print(a, endl="\n"  )
            a, b = b, a+b
        return Done
#end 


fib(22) [enter] prints

PHP Code:

0
1
1
2
3
5
8
13 


PHP Code:

#cas
def legendre_( n, evalX="" ):
    local px, x, type2arg; purge(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)-1 do   
      for row_ from 0 to rowDim(m)-1 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 = [2, 3, 5, 7]
for prime in primes:
    print( prime, endl=" ") 


[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(x, endl=" ")
print("")

# Prints out 3 4 5
for x in range(3, 6):
    print(x, endl=" ")
print("")

# Prints out 3 5 7
for x in range(3, 8, 2):
    print(x, endl=" ") 


[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 x % 2 == 0:
         continue
    print( x, endl=" ") 


[enter]

returns 1
print on console
1 3 5 7 9