js通过正则表达式，判断⽂件类型getFileType (url) {
let pdfReg = /^.+(\.pdf)$/
let txtReg = /^.+(\.txt)$/
let wordReg = /^.+(\.doc|\.docx)$/
let excelReg = /^.+(\.xls|\.xlsx)$/
let jpgReg = /^.+(\.png|\.jpg|\.jpeg|\.bmp)$/
if (st(url)) {
return 'pdf'
}
if (st(url)) {
return 'txt'
}
if (st(url)) {
return 'word'
}
python正则表达式判断if (st(url)) {
return 'excel'
}
if (st(url)) {
return 'picture'
}
}