Move some toplevel strings into the only functions that use them.

Author: anntzer

lib/matplotlib/__init__.py

@@ -882,15 +882,14 @@ def _open_file_or_url(fname):
             yield f
 
 
-_error_details_fmt = 'line #%d\n\t"%s"\n\tin file "%s"'
-
-
 def _rc_params_in_file(fname, fail_on_error=False):
     """Return :class:`matplotlib.RcParams` from the contents of the given file.
 
     Unlike `rc_params_from_file`, the configuration class only contains the
     parameters specified in the file (i.e. default values are not filled in).
     """
+    _error_details_fmt = 'line #%d\n\t"%s"\n\tin file "%s"'
+
     rc_temp = {}
     with _open_file_or_url(fname) as fd:
         try:

lib/matplotlib/mlab.py

@@ -1067,11 +1067,6 @@ def specgram(x, NFFT=None, Fs=None, detrend=None, window=None,
     return spec, freqs, t
 
 
-_coh_error = """Coherence is calculated by averaging over *NFFT*
-length segments.  Your signal is too short for your choice of *NFFT*.
-"""
-
-
 @docstring.dedent_interpd
 def cohere(x, y, NFFT=256, Fs=2, detrend=detrend_none, window=window_hanning,
            noverlap=0, pad_to=None, sides='default', scale_by_freq=None):
@@ -1109,9 +1104,10 @@ def cohere(x, y, NFFT=256, Fs=2, detrend=detrend_none, window=window_hanning,
         For information about the methods used to compute :math:`P_{xy}`,
         :math:`P_{xx}` and :math:`P_{yy}`.
     """
-
     if len(x) < 2 * NFFT:
-        raise ValueError(_coh_error)
+        raise ValueError(
+            "Coherence is calculated by averaging over *NFFT* length "
+            "segments.  Your signal is too short for your choice of *NFFT*.")
     Pxx, f = psd(x, NFFT, Fs, detrend, window, noverlap, pad_to, sides,
                  scale_by_freq)
     Pyy, f = psd(y, NFFT, Fs, detrend, window, noverlap, pad_to, sides,