Fix pylint 2.11 consider-using-f-string checker errors (#1517)

* Use f-strings throughout the project
* Fix C0201 consider-iterating-dictionary
* Fix W1514 unspecified-encoding

Author: weiji14

doc/conf.py

@@ -127,11 +127,9 @@
 release = __version__
 
 # These enable substitutions using |variable| in the rst files
-rst_epilog = """
+rst_epilog = f"""
 .. |year| replace:: {year}
-""".format(
-    year=year
-)
+"""
 
 html_last_updated_fmt = "%b %d, %Y"
 html_title = "PyGMT"

pygmt/__init__.py

@@ -77,7 +77,7 @@ def print_clib_info():
     lines = ["GMT library information:"]
     with Session() as ses:
         for key in sorted(ses.info):
-            lines.append("  {}: {}".format(key, ses.info[key]))
+            lines.append(f"  {key}: {ses.info[key]}")
     print("\n".join(lines))
 
 
@@ -212,7 +212,7 @@ def test(doctest=True, verbose=True, coverage=False, figures=True):
     if verbose:
         args.append("-vv")
     if coverage:
-        args.append("--cov={}".format(package))
+        args.append(f"--cov={package}")
         args.append("--cov-report=term-missing")
     if doctest:
         args.append("--doctest-modules")

pygmt/clib/session.py

@@ -113,9 +113,7 @@ class Session:
     ...         with GMTTempFile() as fout:
     ...             # Call the grdinfo module with the virtual file as input
     ...             # and the temp file as output.
-    ...             ses.call_module(
-    ...                 "grdinfo", "{} -C ->{}".format(fin, fout.name)
-    ...             )
+    ...             ses.call_module("grdinfo", f"{fin} -C ->{fout.name}")
     ...             # Read the contents of the temp file before it's deleted.
     ...             print(fout.read().strip())
     ...
@@ -189,9 +187,8 @@ def __enter__(self):
         if Version(version) < Version(self.required_version):
             self.destroy()
             raise GMTVersionError(
-                "Using an incompatible GMT version {}. Must be equal or newer than {}.".format(
-                    version, self.required_version
-                )
+                f"Using an incompatible GMT version {version}. "
+                f"Must be equal or newer than {self.required_version}."
             )
         return self
 
@@ -366,7 +363,7 @@ def print_func(file_pointer, message):  # pylint: disable=unused-argument
 
         if session is None:
             raise GMTCLibError(
-                "Failed to create a GMT API session:\n{}".format(self._error_message)
+                f"Failed to create a GMT API session:\n{self._error_message}"
             )
 
         self.session_pointer = session
@@ -412,7 +409,7 @@ def destroy(self):
         status = c_destroy_session(self.session_pointer)
         if status:
             raise GMTCLibError(
-                "Failed to destroy GMT API session:\n{}".format(self._error_message)
+                f"Failed to destroy GMT API session:\n{self._error_message}"
             )
 
         self.session_pointer = None
@@ -462,9 +459,7 @@ def get_default(self, name):
 
         if status != 0:
             raise GMTCLibError(
-                "Error getting default value for '{}' (error code {}).".format(
-                    name, status
-                )
+                f"Error getting default value for '{name}' (error code {status})."
             )
 
         return value.value.decode()
@@ -503,9 +498,7 @@ def call_module(self, module, args):
         )
         if status != 0:
             raise GMTCLibError(
-                "Module '{}' failed with status code {}:\n{}".format(
-                    module, status, self._error_message
-                )
+                f"Module '{module}' failed with status code {status}:\n{self._error_message}"
             )
 
     def create_data(self, family, geometry, mode, **kwargs):
@@ -650,30 +643,24 @@ def _parse_constant(self, constant, valid, valid_modifiers=None):
         nmodifiers = len(parts) - 1
         if nmodifiers > 1:
             raise GMTInvalidInput(
-                "Only one modifier is allowed in constants, {} given: '{}'".format(
-                    nmodifiers, constant
-                )
+                f"Only one modifier is allowed in constants, {nmodifiers} given: '{constant}'"
             )
         if nmodifiers > 0 and valid_modifiers is None:
             raise GMTInvalidInput(
                 "Constant modifiers not allowed since valid values were not "
-                + "given: '{}'".format(constant)
+                + f"given: '{constant}'"
             )
         if name not in valid:
             raise GMTInvalidInput(
-                "Invalid constant argument '{}'. Must be one of {}.".format(
-                    name, str(valid)
-                )
+                f"Invalid constant argument '{name}'. Must be one of {str(valid)}."
             )
         if (
             nmodifiers > 0
             and valid_modifiers is not None
             and parts[1] not in valid_modifiers
         ):
             raise GMTInvalidInput(
-                "Invalid constant modifier '{}'. Must be one of {}.".format(
-                    parts[1], str(valid_modifiers)
-                )
+                f"Invalid constant modifier '{parts[1]}'. Must be one of {str(valid_modifiers)}."
             )
         integer_value = sum(self[part] for part in parts)
         return integer_value
@@ -905,7 +892,7 @@ def put_matrix(self, dataset, matrix, pad=0):
             self.session_pointer, dataset, gmt_type, pad, matrix_pointer
         )
         if status != 0:
-            raise GMTCLibError("Failed to put matrix of type {}.".format(matrix.dtype))
+            raise GMTCLibError(f"Failed to put matrix of type {matrix.dtype}.")
 
     def write_data(self, family, geometry, mode, wesn, output, data):
         """
@@ -974,7 +961,7 @@ def write_data(self, family, geometry, mode, wesn, output, data):
             data,
         )
         if status != 0:
-            raise GMTCLibError("Failed to write dataset to '{}'".format(output))
+            raise GMTCLibError(f"Failed to write dataset to '{output}'")
 
     @contextmanager
     def open_virtual_file(self, family, geometry, direction, data):
@@ -1036,7 +1023,7 @@ def open_virtual_file(self, family, geometry, direction, data):
         ...     with lib.open_virtual_file(*vfargs) as vfile:
         ...         # Send the output to a temp file so that we can read it
         ...         with GMTTempFile() as ofile:
-        ...             args = "{} ->{}".format(vfile, ofile.name)
+        ...             args = f"{vfile} ->{ofile.name}"
         ...             lib.call_module("info", args)
         ...             print(ofile.read().strip())
         ...
@@ -1083,7 +1070,7 @@ def open_virtual_file(self, family, geometry, direction, data):
         finally:
             status = c_close_virtualfile(self.session_pointer, vfname.encode())
             if status != 0:
-                raise GMTCLibError("Failed to close virtual file '{}'.".format(vfname))
+                raise GMTCLibError(f"Failed to close virtual file '{vfname}'.")
 
     @contextmanager
     def virtualfile_from_vectors(self, *vectors):
@@ -1131,9 +1118,7 @@ def virtualfile_from_vectors(self, *vectors):
         ...     with ses.virtualfile_from_vectors(x, y, z) as fin:
         ...         # Send the output to a file so that we can read it
         ...         with GMTTempFile() as fout:
-        ...             ses.call_module(
-        ...                 "info", "{} ->{}".format(fin, fout.name)
-        ...             )
+        ...             ses.call_module("info", f"{fin} ->{fout.name}")
         ...             print(fout.read().strip())
         ...
         <vector memory>: N = 3 <1/3> <4/6> <7/9>
@@ -1244,9 +1229,7 @@ def virtualfile_from_matrix(self, matrix):
         ...     with ses.virtualfile_from_matrix(data) as fin:
         ...         # Send the output to a file so that we can read it
         ...         with GMTTempFile() as fout:
-        ...             ses.call_module(
-        ...                 "info", "{} ->{}".format(fin, fout.name)
-        ...             )
+        ...             ses.call_module("info", f"{fin} ->{fout.name}")
         ...             print(fout.read().strip())
         ...
         <matrix memory>: N = 4 <0/9> <1/10> <2/11>
@@ -1327,7 +1310,7 @@ def virtualfile_from_grid(self, grid):
         ...     with ses.virtualfile_from_grid(data) as fin:
         ...         # Send the output to a file so that we can read it
         ...         with GMTTempFile() as fout:
-        ...             args = "{} -L0 -Cn ->{}".format(fin, fout.name)
+        ...             args = f"{fin} -L0 -Cn ->{fout.name}"
         ...             ses.call_module("grdinfo", args)
         ...             print(fout.read().strip())
         ...
@@ -1508,7 +1491,7 @@ def extract_region(self):
         >>> with Session() as lib:
         ...     wesn = lib.extract_region()
         ...
-        >>> print(", ".join(["{:.2f}".format(x) for x in wesn]))
+        >>> print(", ".join([f"{x:.2f}" for x in wesn]))
         0.00, 10.00, -20.00, -10.00
 
         Using ISO country codes for the regions (for example ``'US.HI'`` for
@@ -1521,7 +1504,7 @@ def extract_region(self):
         >>> with Session() as lib:
         ...     wesn = lib.extract_region()
         ...
-        >>> print(", ".join(["{:.2f}".format(x) for x in wesn]))
+        >>> print(", ".join([f"{x:.2f}" for x in wesn]))
         -164.71, -154.81, 18.91, 23.58
 
         The country codes can have an extra argument that rounds the region a
@@ -1535,7 +1518,7 @@ def extract_region(self):
         >>> with Session() as lib:
         ...     wesn = lib.extract_region()
         ...
-        >>> print(", ".join(["{:.2f}".format(x) for x in wesn]))
+        >>> print(", ".join([f"{x:.2f}" for x in wesn]))
         -165.00, -150.00, 15.00, 25.00
         """
         c_extract_region = self.get_libgmt_func(

pygmt/figure.py

@@ -73,7 +73,7 @@ class Figure:
     >>> fig = Figure()
     >>> fig.basemap(region="JP", projection="M3i", frame=True)
     >>> # The fig.region attribute shows the WESN bounding box for the figure
-    >>> print(", ".join("{:.2f}".format(i) for i in fig.region))
+    >>> print(", ".join(f"{i:.2f}" for i in fig.region))
     122.94, 145.82, 20.53, 45.52
     """
 
@@ -103,7 +103,7 @@ def _activate_figure(self):
         # Passing format '-' tells pygmt.end to not produce any files.
         fmt = "-"
         with Session() as lib:
-            lib.call_module("figure", "{} {}".format(self._name, fmt))
+            lib.call_module("figure", f"{self._name} {fmt}")
 
     def _preprocess(self, **kwargs):
         """
@@ -358,9 +358,9 @@ def shift_origin(self, xshift=None, yshift=None):
         self._preprocess()
         args = ["-T"]
         if xshift:
-            args.append("-X{}".format(xshift))
+            args.append(f"-X{xshift}")
         if yshift:
-            args.append("-Y{}".format(yshift))
+            args.append(f"-Y{yshift}")
 
         with Session() as lib:
             lib.call_module("plot", " ".join(args))

pygmt/helpers/decorators.py

@@ -468,7 +468,7 @@ def fmt_docstring(module_func):
         aliases = ["**Aliases:**\n"]
         for arg in sorted(module_func.aliases):
             alias = module_func.aliases[arg]
-            aliases.append("- {} = {}".format(arg, alias))
+            aliases.append(f"- {arg} = {alias}")
         filler_text["aliases"] = "\n".join(aliases)
 
     filler_text["table-like"] = " or ".join(
@@ -634,15 +634,12 @@ def kwargs_to_strings(**conversions):
     ...     "A module that prints the arguments it received"
     ...     print("{", end="")
     ...     print(
-    ...         ", ".join(
-    ...             "'{}': {}".format(k, repr(kwargs[k]))
-    ...             for k in sorted(kwargs)
-    ...         ),
+    ...         ", ".join(f"'{k}': {repr(kwargs[k])}" for k in sorted(kwargs)),
     ...         end="",
     ...     )
     ...     print("}")
     ...     if args:
-    ...         print("args:", " ".join("{}".format(x) for x in args))
+    ...         print("args:", " ".join(f"{x}" for x in args))
     >>> module(R=[1, 2, 3, 4])
     {'R': '1/2/3/4'}
     >>> # It's already a string, do nothing
@@ -690,7 +687,7 @@ def kwargs_to_strings(**conversions):
     for arg, fmt in conversions.items():
         if fmt not in valid_conversions:
             raise GMTInvalidInput(
-                "Invalid conversion type '{}' for argument '{}'.".format(fmt, arg)
+                f"Invalid conversion type '{fmt}' for argument '{arg}'."
             )
 
     separators = {

pygmt/helpers/testing.py

@@ -113,8 +113,9 @@ def wrapper(*args, ext="png", request=None, **kwargs):
                     for key in ["actual", "expected", "diff"]:
                         err[key] = os.path.relpath(err[key])
                     raise GMTImageComparisonFailure(
-                        "images not close (RMS %(rms).3f):\n\t%(actual)s\n\t%(expected)s "
-                        % err
+                        f"images not close (RMS {err['rms']:.3f}):\n"
+                        f"\t{err['actual']}\n"
+                        f"\t{err['expected']}"
                     )
             finally:
                 del fig_ref

pygmt/src/config.py

@@ -55,9 +55,7 @@ def __init__(self, **kwargs):
                     self.old_defaults[key] = lib.get_default(key)
 
         # call gmt set to change GMT defaults
-        arg_str = " ".join(
-            ["{}={}".format(key, value) for key, value in kwargs.items()]
-        )
+        arg_str = " ".join([f"{key}={value}" for key, value in kwargs.items()])
         with Session() as lib:
             lib.call_module("set", arg_str)
 
@@ -67,7 +65,7 @@ def __enter__(self):
     def __exit__(self, exc_type, exc_value, traceback):
         # revert to initial values
         arg_str = " ".join(
-            ["{}={}".format(key, value) for key, value in self.old_defaults.items()]
+            [f"{key}={value}" for key, value in self.old_defaults.items()]
         )
         with Session() as lib:
             lib.call_module("set", arg_str)

pygmt/src/grd2cpt.py

@@ -167,7 +167,7 @@ def grd2cpt(grid, **kwargs):
         with file_context as infile:
             if "H" not in kwargs.keys():  # if no output is set
                 arg_str = " ".join([infile, build_arg_string(kwargs)])
-            elif "H" in kwargs.keys():  # if output is set
+            if "H" in kwargs:  # if output is set
                 outfile = kwargs.pop("H")
                 if not outfile or not isinstance(outfile, str):
                     raise GMTInvalidInput("'output' should be a proper file name.")

pygmt/src/legend.py

@@ -86,6 +86,6 @@ def legend(self, spec=None, position="JTR+jTR+o0.2c", box="+gwhite+p1p", **kwarg
         elif data_kind(spec) == "file":
             specfile = spec
         else:
-            raise GMTInvalidInput("Unrecognized data type: {}".format(type(spec)))
+            raise GMTInvalidInput(f"Unrecognized data type: {type(spec)}")
         arg_str = " ".join([specfile, build_arg_string(kwargs)])
         lib.call_module("legend", arg_str)

pygmt/src/makecpt.py

@@ -149,9 +149,9 @@ def makecpt(**kwargs):
     with Session() as lib:
         if "W" in kwargs and "Ww" in kwargs:
             raise GMTInvalidInput("Set only categorical or cyclic to True, not both.")
-        if "H" not in kwargs.keys():  # if no output is set
+        if "H" not in kwargs:  # if no output is set
             arg_str = build_arg_string(kwargs)
-        elif "H" in kwargs.keys():  # if output is set
+        elif "H" in kwargs:  # if output is set
             outfile = kwargs.pop("H")
             if not outfile or not isinstance(outfile, str):
                 raise GMTInvalidInput("'output' should be a proper file name.")

pygmt/src/meca.py

@@ -455,7 +455,7 @@ def update_pointers(data_pointers):
         elif kind == "file":
             file_context = dummy_context(spec)
         else:
-            raise GMTInvalidInput("Unrecognized data type: {}".format(type(spec)))
+            raise GMTInvalidInput(f"Unrecognized data type: {type(spec)}")
         with file_context as fname:
             arg_str = " ".join([fname, build_arg_string(kwargs)])
             lib.call_module("meca", arg_str)

pygmt/src/surface.py

@@ -105,7 +105,7 @@ def surface(x=None, y=None, z=None, data=None, **kwargs):
             elif kind == "vectors":
                 file_context = lib.virtualfile_from_vectors(x, y, z)
             else:
-                raise GMTInvalidInput("Unrecognized data type: {}".format(type(data)))
+                raise GMTInvalidInput(f"Unrecognized data type: {type(data)}")
             with file_context as infile:
                 if "G" not in kwargs.keys():  # if outgrid is unset, output to tmpfile
                     kwargs.update({"G": tmpfile.name})

pygmt/src/x2sys_cross.py

@@ -202,7 +202,7 @@ def x2sys_cross(tracks=None, outfile=None, **kwargs):
                 # $X2SYS_HOME/TAGNAME/TAGNAME.tag file
                 lastline = (
                     Path(os.environ["X2SYS_HOME"], kwargs["T"], f"{kwargs['T']}.tag")
-                    .read_text()
+                    .read_text(encoding="utf8")
                     .strip()
                     .split("\n")[-1]
                 )  # e.g. "-Dxyz -Etsv -I1/1"