Equivalent of Paste R to Python

Question

I am a new python afficionado. For R users, there is one function : paste that helps to concatenate two or more variables in a dataframe. It's very useful. For example Suppose that I have this dataframe :

   categorie titre tarifMin  lieu  long   lat   img dateSortie 1      zoo,  Aquar      0.0 Aquar 2.385 48.89 ilo,0            2      zoo,  Aquar      4.5 Aquar 2.408 48.83 ilo,0            6      lieu  Jardi      0.0 Jardi 2.320 48.86 ilo,0            7      lieu  Bois       0.0 Bois  2.455 48.82 ilo,0            13     espac Canal      0.0 Canal 2.366 48.87 ilo,0            14     espac Canal     -1.0 Canal 2.384 48.89 ilo,0            15     parc  Le Ma     20.0 Le Ma 2.353 48.87 ilo,0  

I want to create a new column which uses another column in a dataframe and some text. With R, I do :

> y$thecolThatIWant=ifelse(y$tarifMin!=-1, +                             paste("Evenement permanent  -->",y$categorie, +                                   y$titre,"C  partir de",y$tarifMin,"€uros"), +                             paste("Evenement permanent  -->",y$categorie, +                                   y$titre,"sans prix indique")) 

And the result is :

> y    categorie titre tarifMin  lieu  long   lat   img dateSortie 1      zoo,  Aquar      0.0 Aquar 2.385 48.89 ilo,0            2      zoo,  Aquar      4.5 Aquar 2.408 48.83 ilo,0            6      lieu  Jardi      0.0 Jardi 2.320 48.86 ilo,0            7      lieu  Bois       0.0 Bois  2.455 48.82 ilo,0            13     espac Canal      0.0 Canal 2.366 48.87 ilo,0            14     espac Canal     -1.0 Canal 2.384 48.89 ilo,0            15     parc  Le Ma     20.0 Le Ma 2.353 48.87 ilo,0                                                            thecolThatIWant 1  Evenement permanent  --> zoo,  Aquar C  partir de  0.0 €uros 2  Evenement permanent  --> zoo,  Aquar C  partir de  4.5 €uros 6  Evenement permanent  --> lieu  Jardi C  partir de  0.0 €uros 7  Evenement permanent  --> lieu  Bois  C  partir de  0.0 €uros 13 Evenement permanent  --> espac Canal C  partir de  0.0 €uros 14 Evenement permanent  --> espac Canal C  partir de -1.0 €uros 15 Evenement permanent  --> parc  Le Ma C  partir de 20.0 €uros 

My question is : How can I do the same thing in Python Pandas or some other module?

What I've tried so far: Well, I'm a very new user. So sorry for my mistake. I try to replicate the example in Python and we suppose that I get something like this

table=pd.read_csv("y.csv",sep=",") tt= table.loc[:,['categorie','titre','tarifMin','long','lat','lieu']] table ategorie    titre   tarifMin    long    lat     lieu 0   zoo,    Aquar   0.0     2.385   48.89   Aquar 1   zoo,    Aquar   4.5     2.408   48.83   Aquar 2   lieu    Jardi   0.0     2.320   48.86   Jardi 3   lieu    Bois    0.0     2.455   48.82   Bois 4   espac   Canal   0.0     2.366   48.87   Canal 5   espac   Canal   -1.0    2.384   48.89   Canal 6   parc    Le Ma   20.0    2.353   48.87   Le Ma 

I tried this basically

sc="Even permanent -->" + " "+ tt.titre+" "+tt.lieu tt['theColThatIWant'] = sc tt 

And I got this

    categorie   titre   tarifMin    long    lat     lieu    theColThatIWant 0   zoo,    Aquar   0.0     2.385   48.89   Aquar   Even permanent --> Aquar Aquar 1   zoo,    Aquar   4.5     2.408   48.83   Aquar   Even permanent --> Aquar Aquar 2   lieu    Jardi   0.0     2.320   48.86   Jardi   Even permanent --> Jardi Jardi 3   lieu    Bois    0.0     2.455   48.82   Bois    Even permanent --> Bois Bois 4   espac   Canal   0.0     2.366   48.87   Canal   Even permanent --> Canal Canal 5   espac   Canal   -1.0    2.384   48.89   Canal   Even permanent --> Canal Canal 6   parc    Le Ma   20.0    2.353   48.87   Le Ma   Even permanent --> Le Ma Le Ma 

Now, I suppose that I have to loop with condition if there is no vectorize like in R?

Answer 1

This very much works like Paste command in R: R code:

 words = c("Here", "I","want","to","concatenate","words","using","pipe","delimeter")  paste(words,collapse="|") 

[1]

"Here|I|want|to|concatenate|words|using|pipe|delimeter"

Python:

words = ["Here", "I","want","to","concatenate","words","using","pipe","delimeter"] "|".join(words) 

Result:

'Here|I|want|to|concatenate|words|using|pipe|delimeter'

Answer 2

Here's a simple implementation that works on lists, and probably other iterables. Warning: it's only been lightly tested, and only in Python 3.5+:

from functools import reduce  def _reduce_concat(x, sep=""):     return reduce(lambda x, y: str(x) + sep + str(y), x)          def paste(*lists, sep=" ", collapse=None):     result = map(lambda x: _reduce_concat(x, sep=sep), zip(*lists))     if collapse is not None:         return _reduce_concat(result, sep=collapse)     return list(result)  assert paste([1,2,3], [11,12,13], sep=',') == ['1,11', '2,12', '3,13'] assert paste([1,2,3], [11,12,13], sep=',', collapse=";") == '1,11;2,12;3,13' 

You can also have some more fun and replicate other functions like paste0:

from functools import partial  paste0 = partial(paste, sep="") 

Edit: here's a Repl.it project with type-annotated versions of this code.