diff --git a/mapytex/calculus/API/expression.py b/mapytex/calculus/API/expression.py
index be39eda..5f3fe63 100644
--- a/mapytex/calculus/API/expression.py
+++ b/mapytex/calculus/API/expression.py
@@ -97,7 +97,7 @@ class Expression(object):
         :example:
         >>> Expression.random("{a}/{a*k}") # doctest: +SKIP
         <Exp: -3 / -15>
-        >>> Expression.random("{a}/{a*k} - 3*{b}", variables_scope={'a':{'min_max':(10, 30)}}) # doctest +SKIP
+        >>> Expression.random("{a}/{a*k} - 3*{b}", variables_scope={'a':{'min_max':(10, 30)}}) # doctest: +SKIP
         <Exp: 18 / 108 - 3 * 9>
 
         """
diff --git a/mapytex/calculus/core/random/__init__.py b/mapytex/calculus/core/random/__init__.py
index ee6afb9..70bbe24 100644
--- a/mapytex/calculus/core/random/__init__.py
+++ b/mapytex/calculus/core/random/__init__.py
@@ -7,7 +7,7 @@
 # Distributed under terms of the MIT license.
 
 """
-Tools to extract random nodes, random variables, generate random values and
+Tools to extract random leafs, random variables, generate random values and
 fill new trees
 
 Flow
@@ -15,9 +15,9 @@ Flow
 
 Tree with RdLeaf
 |
-| Extract nodes
+| Extract rdLeaf
 |
-List of nodes to generate
+List of leafs to generate
 |
 | extract_rv
 |
@@ -27,9 +27,9 @@ List random variables to generate
 |
 Dictionnary of generated random variables
 |
-| Compute nodes
+| Compute leafs
 |
-Dictionnary of computed nodes
+Dictionnary of computed leafs
 |
 | Replace
 |
diff --git a/mapytex/calculus/core/str2.py b/mapytex/calculus/core/str2.py
index 85cf785..a7098d4 100644
--- a/mapytex/calculus/core/str2.py
+++ b/mapytex/calculus/core/str2.py
@@ -836,6 +836,31 @@ def rdstr2(sink):
     return pipeline
 
 
+def rdstr2(sink):
+    """ Return a pipeline which parse random expression and with sink as endpoint
+
+    :example:
+    >>> rdstr2list = rdstr2(list_sink)
+    >>> rdstr2list("{a}+{a*b}-2")
+    [<RdLeaf a>, '+', <RdLeaf a*b>, '+', <MOnumber - 2>]
+    """
+    lfop = lookfor(is_operator)
+    operator_corout = partial(concurent_broadcast, lookfors=[lfop])
+
+    def pipeline(expression):
+        str2_corout = look_for_rdleaf(
+            lookforNumbers(operator_corout(missing_times(moify_cor(pparser(sink)))))
+        )
+
+        for i in expression.replace(" ", ""):
+            str2_corout.send(i)
+        a = str2_corout.throw(STOOOP)
+
+        return a
+
+    return pipeline
+
+
 str2nestedlist = str2(list_sink)