write/read to/from csv 1st attempt

km3io/write.py

+import os
+import inspect
+import numpy as np
+import km3io as ki
+import awkward as aw
+
+
+CLASSES = tuple(m[1] for m in inspect.getmembers(ki.offline, inspect.isclass))
+
+def to_csv(f_name, **kwargs):
+    """writes data in a csv file
+
+    Parameters
+    ----------
+    f_name : str
+        Description
+    **kwargs
+        Description
+    """
+    if os.path.isfile(f_name):
+        raise OSError("'{}' already exists! change the file name or delete it".format(f_name))
+
+    with open(f_name+'.csv', 'a') as fp:
+        for key, value in kwargs.items(): 
+
+            # write events, hits and tracks classes
+            if isinstance(value, CLASSES):
+                for k, v in zip(value._keys, np.array(value._values)): # if it doesn't work change enumerate(v) to enumerate(np.array(v))
+                    fp.write('# {}\n'.format(k))
+                    for i, j in enumerate(v):
+                        np.savetxt(fp, j, header=str(i), comments='## ')
+
+            # write arrays
+            if isinstance(value, np.ndarray): 
+                np.savetxt(fp, value, header=key, comments='# ')
+
+            else:
+                try:
+                    # write a jagged array
+                    if value.dtype.char == 'O':  # O is the unique char that identifies 'awkward.array.chunked.ChunkedArray'
+                        fp.write('# {}\n'.format(key))
+                        for i, j in enumerate(value):
+                                np.savetxt(fp, j, header=str(i), comments='## ')
+
+                except Exception:
+                    raise TypeError("'{}' is not a valid data structure".format(type(value)))
+
+
+def from_csv(f_name, headers=None):
+    """reads a csv file written by km3io
+
+    Parameters
+    ----------
+    f_name : str
+        Description
+    headers : None, optional
+        list of str of headers
+    """
+    if headers is None:
+        keys = []
+        values = []
+        found_header = False
+        found_sub_header = False
+        # read the entire file
+        with open(f_name, 'r') as fp:
+            jagged_data = []
+            jagged_sub_data = []
+            for line in fp:
+                if '# ' in line:
+                    found_header = True
+                    keys.append(line.split()[1]) # convert str to float
+
+                if found_header:
+                    if '# ' in line:
+                    found_header = False
+                    if '## ' in line:
+                        found_sub_header = True
+                    else:
+                        jagged_data.append(line.split()[0])
+
+
+                if found_header and found_sub_header:
+                    if '## ' in line:
+                        found_sub_header = False
+                        jagged_data.append(jagged_sub_data)
+                    else:
+                        jagged_sub_data.append(lin.split()[0])
+
+
+
+#write in hdf 
+
+
+#write in root (NOT NECESSARY)