Fix cpplint issues

Change-Id: I3421335a578400a40bd392fc9b290cf63f9b3893

cpp/src/arrow/python/common.h

@@ -18,6 +18,8 @@
 #ifndef ARROW_PYTHON_COMMON_H
 #define ARROW_PYTHON_COMMON_H
 
+#include <string>
+
 #include "arrow/python/config.h"
 
 #include "arrow/buffer.h"
@@ -47,7 +49,7 @@ class OwnedRef {
  public:
   OwnedRef() : obj_(nullptr) {}
 
-  OwnedRef(PyObject* obj) : obj_(obj) {}
+  explicit OwnedRef(PyObject* obj) : obj_(obj) {}
 
   ~OwnedRef() {
     PyAcquireGIL lock;
@@ -71,7 +73,7 @@ struct PyObjectStringify {
   OwnedRef tmp_obj;
   const char* bytes;
 
-  PyObjectStringify(PyObject* obj) {
+  explicit PyObjectStringify(PyObject* obj) {
     PyObject* bytes_obj;
     if (PyUnicode_Check(obj)) {
       bytes_obj = PyUnicode_AsUTF8String(obj);
@@ -103,7 +105,7 @@ ARROW_EXPORT MemoryPool* get_memory_pool();
 
 class ARROW_EXPORT NumPyBuffer : public Buffer {
  public:
-  NumPyBuffer(PyArrayObject* arr) : Buffer(nullptr, 0) {
+  explicit NumPyBuffer(PyArrayObject* arr) : Buffer(nullptr, 0) {
     arr_ = arr;
     Py_INCREF(arr);
 
@@ -124,7 +126,7 @@ class ARROW_EXPORT PyBuffer : public Buffer {
   ///
   /// While memoryview objects support multi-demensional buffers, PyBuffer only supports
   /// one-dimensional byte buffers.
-  PyBuffer(PyObject* obj);
+  explicit PyBuffer(PyObject* obj);
   ~PyBuffer();
 
  private:

cpp/src/arrow/python/io.cc

@@ -19,6 +19,7 @@
 
 #include <cstdint>
 #include <cstdlib>
+#include <string>
 
 #include "arrow/io/memory.h"
 #include "arrow/memory_pool.h"
@@ -166,7 +167,7 @@ Status PyReadableFile::GetSize(int64_t* size) {
   PyAcquireGIL lock;
 
   int64_t current_position;
-  ;
+
   ARROW_RETURN_NOT_OK(file_->Tell(&current_position));
 
   ARROW_RETURN_NOT_OK(file_->Seek(0, 2));

cpp/src/arrow/python/io.h

@@ -36,7 +36,7 @@ namespace py {
 // calling any methods
 class PythonFile {
  public:
-  PythonFile(PyObject* file);
+  explicit PythonFile(PyObject* file);
   ~PythonFile();
 
   Status Close();

cpp/src/arrow/python/pandas_convert.cc

@@ -32,6 +32,7 @@
 #include <string>
 #include <thread>
 #include <unordered_map>
+#include <vector>
 
 #include "arrow/array.h"
 #include "arrow/column.h"
@@ -124,7 +125,7 @@ static int64_t ValuesToValidBytes(
 
   // TODO(wesm): striding
   for (int i = 0; i < length; ++i) {
-    valid_bytes[i] = not traits::isnull(values[i]);
+    valid_bytes[i] = !traits::isnull(values[i]);
     if (traits::isnull(values[i])) null_count++;
   }
 
@@ -225,7 +226,7 @@ class PandasConverter : public TypeVisitor {
         type_(type),
         arr_(reinterpret_cast<PyArrayObject*>(ao)),
         mask_(nullptr) {
-    if (mo != nullptr and mo != Py_None) { mask_ = reinterpret_cast<PyArrayObject*>(mo); }
+    if (mo != nullptr && mo != Py_None) { mask_ = reinterpret_cast<PyArrayObject*>(mo); }
     length_ = PyArray_SIZE(arr_);
   }
 
@@ -819,6 +820,7 @@ class PandasBlock {
   OwnedRef placement_arr_;
   int64_t* placement_data_;
 
+ private:
   DISALLOW_COPY_AND_ASSIGN(PandasBlock);
 };
 
@@ -1302,7 +1304,7 @@ class DatetimeTZBlock : public DatetimeBlock {
 template <int ARROW_INDEX_TYPE>
 class CategoricalBlock : public PandasBlock {
  public:
-  CategoricalBlock(int64_t num_rows) : PandasBlock(num_rows, 1) {}
+  explicit CategoricalBlock(int64_t num_rows) : PandasBlock(num_rows, 1) {}
 
   Status Allocate() override {
     constexpr int npy_type = arrow_traits<ARROW_INDEX_TYPE>::npy_type;
@@ -1430,7 +1432,7 @@ using BlockMap = std::unordered_map<int, std::shared_ptr<PandasBlock>>;
 // * placement arrays as we go
 class DataFrameBlockCreator {
  public:
-  DataFrameBlockCreator(const std::shared_ptr<Table>& table) : table_(table) {}
+  explicit DataFrameBlockCreator(const std::shared_ptr<Table>& table) : table_(table) {}
 
   Status Convert(int nthreads, PyObject** output) {
     column_types_.resize(table_->num_columns());

cpp/src/arrow/python/type_traits.h

@@ -18,6 +18,7 @@
 #include <Python.h>
 
 #include <cstdint>
+#include <limits>
 
 #include "arrow/python/numpy_interop.h"