title: How can I remove punctuations and numbers in text from data.frame file in R
body: <p>I want to remove punctuations, numbers and http links in text from data.frame file. I tried tm, stringr, quanteda, tidytext packages but none of them worked. I m looking for a useful basic package or function for clean data.frame file without convert it to corpus or something like that.</p>
  
  <h2>How can I do it?</h2>
  
  <blockquote>
    <p>mycorpus &lt;- tm_map(mycorpus, content_transformer(remove_url))
    Warning message:
    In tm_map.SimpleCorpus(mycorpus, content_transformer(remove_url)) :
    transformation drops documents</p>
    
    <p>mycorpus &lt;- tm_map(mycorpus, removePunctuation)
    Warning message:
    In tm_map.SimpleCorpus(mycorpus, removePunctuation) :
    transformation drops documents</p>
  </blockquote>
  
  <p>And, when I try to see some tweets which contains any symbol:
  Error in nchar(output) : invalid multibyte string, element 1</p>
  
  <blockquote>
    <p>mycorpus &lt;- tm_map(mycorpus, content_transformer(tolower))
    Error in FUN(content(x), ...) : 
      invalid input</p>
  </blockquote>