代码简单实用，话就不多说了。直接贴代码：

'''

Ezone 2020-02-16 @tangkin.com

import PIL from Image

def conv_img(covimg_fn,format=""):

'''
cov to any image format
:param covimg_fn:
:param format:
:return:
'''
if not covimg_fn:
    print("None image file to convert!")
    exit()
outfile=""
for infile in covimg_fn:
    f, e = os.path.splitext(infile)
    if format.lower() == ("jpg", "jpeg"):
        outfile = f + ".jpg"
        print(outfile)
    elif format.lower()=="gif":
        outfile = f + ".gif"
        print(outfile)
    elif format.lower() == "png":
        outfile = f + ".png"
        print(outfile)
    elif format.lower()=="bmp":
        outfile = f + ".bmp"
        print(outfile)
    elif format.lower() == "tiff":
        outfile = f + ".tiff"
        print(outfile)
    else:
        print("Usage:Command <jpg|gif|bmp|png> filename1,filename2 ... ...")
        exit()

    if infile != outfile:
        try:
            Image.open(infile).save(outfile)
        except IOError:
            print("cannot convert:", infile)

if name == '__main__':

#change value you want
#"jpg,gif,tiff,bmp,png"
covimg_format=“jpg”
#images path of list or str 
covimg_fn=[1.gif,2,gif,3.gif,4.tiff]
conv_img(covimg_fn,covimg_format)

'''