CLN: misc cleanups from LGTM

Author: simonjayhawkins

pandas/_testing.py

@@ -248,16 +248,10 @@ def write_to_compressed(compression, path, data, dest="test"):
     ValueError : An invalid compression value was passed in.
     """
     if compression == "zip":
-        import zipfile
-
         compress_method = zipfile.ZipFile
     elif compression == "gzip":
-        import gzip
-
         compress_method = gzip.GzipFile
     elif compression == "bz2":
-        import bz2
-
         compress_method = bz2.BZ2File
     elif compression == "xz":
         compress_method = _get_lzma_file(lzma)

pandas/core/frame.py

@@ -8216,7 +8216,6 @@ def blk_func(values):
                     result = result.iloc[0].rename(None)
                 return result
 
-        data = self
         if numeric_only is None:
             data = self
             values = data.values

pandas/core/series.py

@@ -276,7 +276,6 @@ def __init__(
                         "Cannot construct a Series from an ndarray with "
                         "compound dtype.  Use DataFrame instead."
                     )
-                pass
             elif isinstance(data, ABCSeries):
                 if index is None:
                     index = data.index