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

Answer 1

1. You can trypandas.Series.str.cat

   import pandas as pd
   def paste0(ss,sep=None,na_rep=None,):
       '''Analogy to R paste0'''
       ss = [pd.Series(s) for s in ss]
       ss = [s.astype(str) for s in ss]
       s = ss[0]
       res = s.str.cat(ss[1:],sep=sep,na_rep=na_rep)
       return res
   
   pasteA=paste0
   

2. Or just sep.join()

   #

   def paste0(ss,sep=None,na_rep=None, 
       castF=unicode, ##### many languages dont work well with str
   ):
       if sep is None:
           sep=''
       res = [castF(sep).join(castF(s) for s in x) for x in zip(*ss)]
       return res
   pasteB = paste0
   
   
   %timeit pasteA([range(1000),range(1000,0,-1)],sep='_')
   # 100 loops, best of 3: 7.11 ms per loop
   %timeit pasteB([range(1000),range(1000,0,-1)],sep='_')
   # 100 loops, best of 3: 2.24 ms per loop
   

3. I have used itertools to mimic recycling

   import itertools
   def paste0(ss,sep=None,na_rep=None,castF=unicode):
       '''Analogy to R paste0
       '''
       if sep is None:
           sep=u''
       L = max([len(e) for e in ss])
       it = itertools.izip(*[itertools.cycle(e) for e in ss])
       res = [castF(sep).join(castF(s) for s in next(it) ) for i in range(L)]
       # res = pd.Series(res)
       return res
   

4. patsy might be relevant (not an experienced user myself.)